Keston System 30Kw Installation Manual

Keston system 30 installation instructions Keston system 30 installation instructions

2015-05-15

: Keston Keston-System-30Kw-Installation-Manual-719640 keston-system-30kw-installation-manual-719640 keston pdf

Open the PDF directly: View PDF .
Page Count: 68

Download
Open PDF In Browser	View PDF

System 30
Installation and Servicing Instructions
FAN POWERED HIGH EFFICIENCY
MODULATING DOMESTIC CONDENSING
GAS BOILER
CE/PI No. 86-CL-08
System 30 - GC No. 41-930-39

These instructions must be left either with the
user or next to the site gas meter.
Keston Heating
PO Box 103, National Avenue, Kingston Upon Hull, HU5 4JN
Tel. +44 (0) 1482 443005 Fax. +44 (0) 1482 467133
email : info@keston.co.uk web : www.keston.co.uk
COMPLIANT WITH BUILDING REGULATION PART L1 & L2
SEDBUK A RATED

Keston System - Installation and Servicing

Notes for the installer
For any technical queries pleAse ring the KESTON
installer/technical helpline : 01482 443005
NOTE. BOILER RESET PROCEDURE To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
The boiler will repeat the ignition sequence if a heat demand is present.

DOCUMENT amendments
Relevant Installation changes implemented in this book from Mod Level......... A03 (Oct 13) to A04 (Feb 14)
Page 10
4.b. - Statement updated
Page 30
Item 3 added to Electrical Installation
Statement added ref to commissioning process of combustion
Page 57
New Page Added - Benchmark Commissiong & Servicing Section
Page 58 & 59
New updated Commissioning Checklist & Service Record Sheets
Page 60 & 61
New pages added, Flowchart for CO Level and Combustion Ratio Check on Commissioning a Condensing Boiler

Keston reserve the right to vary specification without notice

Keston System - Installation and Servicing

general
Table 1 - General Data
Keston System
30
Gas supply
2H - G20 - 20mbar
Gas Supply Connection
15mm copper compression
Injector Size
(mm)
4.65
Flow Connection
Central Heating
22mm copper compression
Return Connection
Central Heating
22mm copper compression
Flue Terminal Diameter
mm (in)
50 (2)
Average Flue Temp-Mass Flow Rate
69oC - 13g/s
Maximum Working Pressure (Sealed Systems)
bar (lb/in2)
2.5 (36.3)
Electrical Supply
230 V ~ 50 Hz.
Power Consumption
W
152
Fuse Rating
External : 3A Internal : T4H HRC L250 V
Water content
litre (gal)
1.2 (0.26)
Packaged Weight
kg (lb)
34.5 (76)
Maximum Installation Weight
kg (lb)
28 (61.7)
Boiler Casing Size
Height
mm (in)
700 (27.5)

Width
mm (in)
395 (15.5)

Depth
mm (in)
278 (11)
Table 2 - Performance Data - Central Heating

MIN

MAX

6.1

30.4

Boiler Input :
Boiler Input ‘Q’

Nett CV

(Btu/h)

Gross CV

(20,700)

(Btu/h)
Gas Consumption

(103.600)

6.7

33.7

(23,000)

m3/h

(115,000)

0.622

3.135

(ft3/h) (22)

(111)

Boiler Output :
Non Condensing kW
70 C Mean Water temp.

(Btu/h)

Condensing

40oC Mean Water temp.

(Btu/h)

6.1

30.3

(20,700)

(103,300)

6.4

31.0

(21,800)

(105,800)

Seasonal efficiency* SEDBUK 2005

91.1%

Seasonal efficiency* SEDBUK 2009

89.6%

NOx Classification

CLASS 5

* The value is used in the UK Government’s Standard Assessment Procedure (SAP) for energy rating of dwellings. The test data from
which it has been calculated have been certified by a notified body.

Note. Gas consumption is calculated using a
calorific value of 38.7 MJ/m3 (1038 Btu/ft3) gross
or 34.9 MJ/m3 (935 Btu/ft3) nett
To obtain the gas consumption at a different
calorific value:
a. For l/s
- divide the gross heat input
(kW) by the gross C.V. of the gas (MJ/m3)
b. For ft3/h - divide the gross heat input (Btu/h)
by the gross C.V. of the gas (Btu/ft3)

Key to symbols
GB = United Kingdom

IE = Ireland

(Countries of destination)

PMS = Maximum operating pressure of water
C13 C53 = A room sealed appliance designed for connection via ducts to a horizontal
terminal, which admits fresh air to the burner and discharges the products
of combustion to the outside. The fan is up stream of the combustion
chamber.
I2H

= An appliance designed for use on 2nd Family gas, Group H only.

c. For m3/h - multiply l/s by 3.6.

Keston System - Installation and Servicing

general

Contents

Keston System
Natural Gas only
Boiler size G.C. Appliance No. PI No.

(Benchmark No.)
30

41-930-39

86 CL 08

Benchmark Commissioning Checklist ...................... 58
Boiler Clearances .......................................................... 9
Boiler Exploded Diagram ............................................ 12
Condensate Drain ................................................... 21,22
Commissioning & Testing .......................................... 30

Destination Country:

GB, IE

Electrical Connections ................................................ 24
Electrical Supply ........................................................... 8
Fault Finding ................................................................ 49
Flue Installation ........................................................... 14
Gas Safety Regulations ................................................ 7
Gas Supply ..................................................................... 8
Initial Lighting ............................................................. 31
Installation .. ............................................................ 14-32
Pump ............................................................................ 46
Safe Handling .. ............................................................... 6
Servicing ................................................................. 33-48
Short List of Parts ....................................................... 55
Thermostatic Radiator Valves ...................................... 8
Water and Systems ............................................ 8,10-11
Water Connections ...................................................... 23
Water Treatment ..........................................................11
Wiring Diagram ............................................................ 29

For GB, to comply with Building Regulations Part L1 (Part 6 in Scotland) the boiler should be fitted in accordance with the
manufacturer’s instructions. Self-certification that the boiler has been installed to comply with Building Regulations can be
demonstrated by completing and signing the Benchmark Commissioning Checklist.
Before installing this boiler, read the Code of Practice sheet at the rear of this book.

Benchmark Commissioning Checklist Details
Boiler

Page

Make and model.......................................................... 5

Appliance serial no. on data badge ........... Front Cover

SEDBUK No. %........................................................... 4
Controls

Time and temperature control to heating.................. 28

Time and temperature control to hot water ............ N/A

Heating zone valves.................................................. 28
TRV’s.......................................................................... 8

Auto bypass................................................................ 8

Boiler interlock............................................................. 8
For ..................................................................... all boilers

Flushing to BS.7593.................................................. 12
Inhibitor..................................................................... 12
Central heating mode
Heat input....................................................to be calculated

Page

Burner operating pressure....................................... n/a

Central heating flow temp.............measure and record

Central heating return temp..........measure and record
For combination boilers only

Scale reducer............................................................ 11
Hot water mode

Heat input.............................................to be calculated

Max. operating burner pressure............................... n/a

Max. operating water pressure......... measure & record

Cold water inlet temp....................... measure & record

Hot water outlet temp....................... measure & record

Water flow rate at max. setting......... measure & record
For condensing boilers only

Condensate drain................................................. 21,22
For all boilers: complete, sign & hand over to customer
For assistance see Technical Helpline on the back page

NOTE TO THE INSTALLER: COMPLETE
THE BENCHMARK COMMISSIONING
CHECKLIST AND LEAVE THESE
INSTRUCTIONS WITH APPLIANCE

Keston System - Installation and Servicing

general
INTRODUCTION
The Keston System boiler is wall mounted, full sequence,
automatic spark ignition, low water content, fanned flue, high
efficiency, condensing, system gas boiler.
Note. Due to the high efficiency of the boiler a plume of water
vapour will form at the flue terminal during operation.

Optional extra kits
•
•
•
•

Air Terminal Finishing Kit
Chronotherm Room Controller
Flue Sleeve Kit
Room Sensor

Central heating (CH) output is fully modulating with a range of:
30

6.1 to 30.3kW (20,700 to 103,300 Btu/h)

The boiler is supplied fully assembled with circulating pump,
pressure gauge, safety valve and CH expansion vessel.
A variable CH temperature control is fitted on the user control.
The boiler includes as standard:
-
Boiler frost protection
-
Daily pump exercise
-
Weather compensation
The boiler casing is of white painted mild steel.
The boiler temperature control is visibly located in the control
panel on the front of the boiler.
The heat exchanger is manufactured from cast aluminium.
The boiler is suitable for connection to fully pumped, sealed
heating systems ONLY. Adequate arrangements for completely
draining the system by provision of drain cocks MUST be provided
in the installation pipework.
Pipework from the boiler is routed downwards.

operation
When there is a demand for CH, the heating system is supplied at
the selected temperature of between 30oC and 80oC.
The boiler features a comprehensive diagnostic system which
gives detailed information on the boiler status when operating,
and performance of key components to aid commissioning and
fault finding.

Safe Handling
This boiler may require 2 or more operatives to move it to its
installation site, remove it from its packaging base and during
movement into its installation location. Manoeuvring the boiler
may include the use of a sack truck and involve lifting, pushing
and pulling.
Caution should be exercised during these operations.
Operatives should be knowledgeable in handling techniques when
performing these tasks and the following precautions should be
considered:
• Grip the boiler at the base.
• Be physically capable.
• Use personal protective equipment as appropriate, e.g.
gloves, safety footwear.
During all manoeuvres and handling actions, every attempt should
be made to ensure the following unless unavoidable and/or the
weight is light.
•
•
•
•
•
•
•

Keep back straight.
Avoid twisting at the waist.
Avoid upper body/top heavy bending.
Always grip with the palm of the hand.
Use designated hand holds.
Keep load as close to the body as possible.
Always use assistance if required.

Keston System - Installation and Servicing

general
Safety

Location of boiler

Current Gas Safety (installation and use) regulations or rules
in force:

The boiler must be installed on a flat and vertical internal wall,
capable of adequately supporting the weight of the boiler and any
ancillary equipment.

The appliance is suitable only for installation in GB and IE and
should be installed in accordance with the rules in force.
In GB, the installation must be carried out by a Gas Safe
Registered Engineer. It must be carried out in accordance with
the relevant requirements of the:
• Gas Safety (Installation and Use) Regulations

The boiler may be fitted on a combustible wall and insulation
between the wall and the boiler is not necessary, unless required
by the local authority.
For electrical safety reasons there must be no access available
from the back of the boiler.

• The appropriate Building Regulations either The Building
Regulations, The Building Regulations (Scotland), Building
Regulations (Northern Ireland).

The boiler must not be fitted outside.

• The Water Fittings Regulations or Water byelaws in Scotland.

If the boiler is to be fitted in a timber framed building it should be
fitted in accordance with the Institute of Gas Engineering document
IGE/UP/7:1998.

• The Current I.E.E. Wiring Regulations.
Where no specific instructions are given, reference should be
made to the relevant British Standard Code of Practice.
In IE, the installation must be carried out by a Registered Gas
Installer (RGII) and installed in accordance with the current edition
of I.S.813 “Domestic Gas Installations”, the current Building
Regulations and reference should be made to the current ETCI
rules for electrical installation.
Detailed recommendations are contained in the following British
Standard Codes of Practice:
BS. 5440:1 Flues (for gas appliances of rated input not
exceeding 70 kW).
BS. 5440:2 Ventilation (for gas appliances of rated input not
exceeding 70 kW).
BSEN. 12828:2003 Heating Systems in buildings: Design for
water based heating systems.
BSEN 12831:2003 Heating Systems in buildings: Method for
calculation of the design heat load.
BSEN 14336:2004

Bathroom Installations
This appliance is rated IP20.
The boiler may be installed in any room or internal space, although
particular attention is drawn to the requirements of the current
IEE (BS.7671) Wiring Regulations and the electrical provisions
of the building regulations applicable in Scotland, with respect to
the installation of the boiler in a room or internal space containing
a bath or shower. For IE reference should be made to the current
ETCI rules for electrical installations and I.S. 813:2002.
If the appliance is to be installed in a room containing a bath or
shower then, providing water jets are not going to be used for
cleaning purposes (as in communal baths/showers), the appliance
must be installed beyond Zone 2, as detailed in BS.7671.
Compartment Installations
Ceiling

Heating Systems in buildings: Installation
and commissioning of water based heating
systems.

BS. 5546

Installation of gas hot water supplies for domestic
purposes (2nd Family Gases)

BS. 6798

Installation of gas fired hot water boilers of rated
input not exceeding 70 kW.

BS. 6891

Timber Framed Buildings

Low pressure installation pipes.

Recessed
window
Zone 2

2.25m

Zone 1

0.6m

Health & Safety Document No. 635.
The Electricity at Work Regulations, 1989.
The manufacturer’s notes must NOT be taken, in any way, as
overriding statutory obligations.
IMPORTANT. These appliances are CE certificated for safety
and performance. It is, therefore, important that no external
control devices, e.g. flue dampers, economisers etc., are
directly connected to these appliances unless covered by
these Installation and Servicing Instructions or as otherwise
recommended by Keston in writing. If in doubt please enquire.
Any direct connection of a control device not approved by Keston
could invalidate the certification and the normal appliance
warranty. It could also infringe the Gas Safety Regulations and
the above regulations.

SAFE HANDLING OF SUBSTANCES
No asbestos, mercury or CFCs are included in any part of the
boiler or its manufacture.

Keston System - Installation and Servicing

Zone 0
3G8913a

A compartment used to enclose the boiler should be designed and
constructed specially for this purpose.
An existing cupboard or compartment may be used, provided that
it is modified for the purpose.
In both cases, details of essential features of cupboard /
compartment design, including airing cupboard installation, are to
conform to the following:
• BS 6798 (No cupboard ventilation is required - see ‘Air Supply’
for details).
• The position selected for installation MUST allow adequate
space for servicing in front of the boiler.
• For the minimum clearances required for safety and
subsequent service, see the wall mounting template and
Frame 1. In addition, sufficient space may be required to
allow lifting access to the wall mounting plate.

general
GAS SUPPLY

Water circulation system

The local gas supplier should be consulted, at the installation
planning stage, in order to establish the availability of an adequate
supply of gas. An existing service pipe must NOT be used without
prior consultation with the local gas supplier.

Important.

The boiler MUST be installed on a gas supply with a governed
meter only.

The central heating system should be in accordance with BS.6798
and, in addition, for smallbore and microbore systems, BS.5449.

A gas meter can only be connected by the local gas supplier or
by a Gas Safe Registered Engineer. In IE by a Registered Gas
Installer (RGII).

Water treatment - see Frame 4

Boiler Control Interlocks

An existing meter should be checked, preferably by the gas
supplier, to ensure that the meter is adequate to deal with the rate
of gas supply required.

Central heating systems controls should be installed to ensure
the boiler is switched off when there is no demand for heating, in
compliance with Building Regulations.

It is the responsibility of the Gas Installer to size the gas
installation pipework in accordance with BS6891:2005. Whilst
the principle of the 1:1 gas valve ensures the Keston range is
able to deliver it’s full output at inlet pressures as low as 14mb,
other gas appliances in the property may not be as tolerant.
When operating pressures are found to be below the minimum
meter outlet of 19mb these should be checked to ensure this is
adequate for correct and safe operation.

Heating systems utilising full thermostatic radiator valve control
of temperature in individual rooms should also be fitted with a
room thermostat controlling the temperature in a space served by
radiators not fitted with such a valve.

Allowing for the acceptable pressure loss of 1mb across the
installation pipework, it can be assumed that a minimum permitted
operating pressure of 18mb will be delivered to the inlet of
the appliance. (Reference BS 6400-1 Clause 6.2 Pressure
Absorption).
The external gas cock could further reduce the operating pressure
when measured at its test point. The pressure drop is relative to
the heat input to the boiler (kW), refer to graph below.

A minimum length of 1 metre of copper pipe MUST be fitted
to both flow and return connections from the boiler before
connection to any plastic piping.

When thermostatic radiator valves are used, the space heating
temperature control over a living / dining area or hallway having
a heating requirement of at least 10% of the minimum boiler heat
output should be achieved using a room thermostat, whilst other
rooms are individually controlled by thermostatic radiator valves.
However, if the system employs thermostatic radiator valves on all
radiators, or two port valves, then a bypass circuit must be fitted
with an automatic bypass valve to ensure a flow of water should
all valves be in the closed position.

Electrical supply
Warning.
This appliance must be earthed.
Wiring external to the appliance MUST be in accordance with
the current I.E.E. (BS.7671) Wiring Regulations and any local
regulations which apply. For IE reference should be made to the
current ETCI rules for electrical installations.
The mains supply to the boiler and system wiring centre shall be
through one common fused double pole isolator. For new heating
systems, and where practicable replacement boiler installations,
the isolator shall be situated adjacent to the appliance.

Condensate drain
Refer to Frames 20, 21 & 41

Installation pipes must be fitted in accordance with BS.6891. In IE
refer to IS.813:2002.

A condensate drain is provided on the boiler. This drain must be
connected to a drainage point on site. All pipework and fittings in
the condensate drainage system MUST be made of plastic - no
other materials may be used.

The complete installation MUST be tested for gas tightness and
purged as described in the above code.

Any external runs must be in accordance with BS 6798.

Important.

Important.
The drain outlet on the boiler is sized for standard 21.5mm (3/4”)
overflow pipe. It is a universal fitting to allow use of different
brands of pipework.

Keston System - Installation and Servicing

general
1 boiler dimensions, services & clearances
The boiler connections are made on the boiler connection tails.
Refer to Frame 23.

wall thicknesses do not exceed 600mm (24”). Where the
space into which the boiler is going to be installed is less
than the length of flue required the flue must be fitted from
the outside.

The following minimum clearances must be maintained for
operation and servicing.
Additional space will be required for installation, depending upon
site conditions.
Side and Rear Flue
a. Provided that the flue hole is cut accurately, e.g. with a core
drill, the flue can be installed from inside the building where

2.5
from case

2.5

Installation from inside ONLY
b. If a core boring tool is to be used inside the building the
space in which the boiler is to be installed must be at least
wide enough to accommodate the tool.

30mm
Minimum Top Clearance

395
62

all dimensions in mm

198
155

89
Air

Flue

700

100 *

395

400

122

104

Gas Inlet

Front clearance
The minimum front clearance when built in to a cupboard is 5mm
from the cupboard door but 450mm overall clearance is still
required, with the cupboard door open, to allow for servicing.

* Bottom clearance

Bottom clearance after installation can be reduced to 5mm.
This must be obtained with an easily removable panel, to enable
the consumer to view the system pressure gauge, and to provide
the 100mm clearance required for servicing.

Keston System - Installation and Servicing

general
2

system requirements - Central Heating

Notes
a. The method of filling, refilling, topping up or flushing sealed primary
hot water circuits from the mains via a temporary hose connection
is only allowed if acceptable to the local water authority.

Safety valve setting bar

b. Antifreeze fluid, corrosion and scale inhibitor fluids suitable for use
with boilers having aluminium heat exchangers may be used in the
central heating system.

System pre-charge pressure bar

General

Vessel charge pressure

bar

System volume

(litres)

3.0

0.5 to 0.75
None

1.0

Expansion vessel
volume (litres)

1.6 1.8

3.1 3.7

2. The installation should be designed to work with flow
temperatures of up to 86 oC.

4.7 5.5

100

6.3 7.4

3. All components of the system must be suitable for a working
pressure of 3 bar and temperature of 110 oC. Extra care should
be taken in making all connections so that the risk of leakage is
minimised.

125

7.8 9.2

150

9.4 11.0

175

10.9 12.9

190

11.9 14.0

200

12.5 14.7

250

15.6 18.4

300

18.8 22.1

1. The installation must comply with all relevant national and local
regulations.

The following components are incorporated within the appliance:

a. Circulating pump.

b. Safety valve, with a non-adjustable preset lift pressure of 3
bar.

c. Pressure gauge, covering a range of 0 to 4 bar.

d. An 8-litre expansion vessel, with an initial charge pressure
of 0.75 bar.

For other system volumes
multiply by the factor across

0.063 0.074

4. ‘Make-up’ Water. Provision must be made for replacing water
loss from the system, either :

a. From a manually filled ‘make-up’ vessel with a readily visible
water level. The vessel should be mounted at least 150mm
above the highest point of the system and be connected
through a non-return valve to the system, fitted at least
150mm below the ‘make-up’ vessel on the return side of
the radiators. or
b. Where access to a ‘make-up’ vessel would be difficult, by
pre-pressurisation of the system.

The maximum cold water capacity of the system should
not exceed 143 litres. This is the maximum system
volume for the boiler expansion vessel. If the capacity of
the vessel is not considered sufficient for this, or for any
other reason, an additional vessel must be installed on
the return to the boiler.

Guidance on vessel sizing is given in table opposite.

Model 30
Max CH uutput
kW
30.3
(Btu/h) (103,300)
Water flow rate l/min
(gal/min)

o
C 20
Temp differential
(oF) (36)

Head available m.w.g.
for system
(ft.w.g.)

5. Filling

CH Return

Hose unions

This may involve the fitting of an additional WRAS approved
isolator valve to the mains supply.

Additional
stop valve

i. Thoroughly flush out the whole system with cold water.
ii. Fill and vent the system until the pressure gauge registers 1.5
bar, and examine for leaks.
iii. Check the operation of the safety valve by raising the water
pressure until the valve lifts. This should occur within 0.3 bar
of the preset lift pressure.

1.9
(6.2)

Mains
water supply

The system may be filled by the following method:
Through a temporary hose connection from a ‘draw-off’ tap,
supplied from a service pipe under mains pressure. Where the
mains pressure is excessive, a pressure reducing valve must be
used to facilitate filling. When installing the filling device, it must
be connected as below to fully comply with the water regulations.

21.5
(4.7)

Temporary hose
(disconnect after filling)
Ecl 6053

Double check valve
assembly
(note direction of flow)

iv. Release water from the system until the minimum system
design pressure is reached; 1.0 bar if the system is to be prepressurised.

Keston System - Installation and Servicing

general
3

system balancing

The boiler does not normally need a bypass but at least some radiators on the heating circuit, of load of at least 10% of the
minimum boiler output, must be provided with twin lockshield valves so that this minimum heating load is always available. See
note regarding thermostatic radiator valves on page 8.
Note. Systems incorporating zone valves which could completely cut off the flow through the system must also include a bypass.

Balancing
1. Set the programmer to ON.

Close the manual or thermostatic valves on all radiators,
leaving the twin lockshield valves (on the radiators referred
to above) in the open position.

Turn up the room thermostat and adjust the lockshield
valve to give an uninterrupted flow through the radiator.

These valves should now be left as set.

2. Open all manual or thermostatic radiator valves and adjust
the lockshield valves on the remaining radiators, to give
around 20oC temperature drop at each radiator.
3. Adjust the room thermostat and programmer to normal
settings.

4 water treatment
Central Heating
The Keston System range of boilers have an aluminium
alloy heat exchanger.

For further information contact:

Important.
The application of any other treatment to this product may
render the guarantee of Keston Invalid.

Fernox Cookson Electronics
Forsyth Road
Sheerwater
Woking
Surrey GU21 5RZ
+44 (0) 0870 601 5000

Keston recommend Water Treatment in accordance with the
Benchmark Guidance Notes on Water Treatment in Central
Heating Systems.
If water treatment is used Keston recommend only the use of

SCALEMASTER GOLD 100, Fernox, MBI, Adey MC1 or Sentinel
X100 inhibitors and associated water treatment products, which

must be used in accordance with the manufacturers’ instructions.
Notes.
1. It is most important that the correct concentration of the
water treatment products is maintained in accordance with
the manufacturers’ instructions.
2. If the boiler is installed in an existing system any unsuitable
additives MUST be removed by thorough cleansing. BS
7593:2006 details the steps necessary to clean a domestic
heating system.
3. In hard water areas, treatment to prevent lime scale may be
necessary - however the use of artificially softened water is
NOT permitted.

Sentinel Performance Solutions
The Heath Business & Technical Park
Runcorn
Cheshire WA7 4QX
Tel: 0800 389 4670
www.sentinel-solutions.net
Scalemaster Water Treatment Products
Emerald Way
Stone
Staffordshire ST15 0SR
Tel: +44 (0) 1785 811636
Calmag Ltd.
Unit 3-6, Crown Works
Bradford Road
Sandbeds, Keighley
West Yorkshire BD20 5LN
Tel: +44 (0) 1535 210 320
Adey Professional Heating Solutions
Gloucester Road,
Cheltenham GL51 8NR
Tel: +44 (0) 1242 546700

4. Under no circumstances should the boiler be fired before the
system has been thoroughly flushed.

Keston System - Installation and Servicing

INSTALLATION

general
5 boiler assembly - exploded view
Note that item numbers are linked to the spares list

104
CH RETURN VALVE
105
CH FLOW VALVE
108
PUMP HEAD
110
Pump Auto Air Vent
113
PRESSURE RELIEF VALVE
114
PIPE - PRV OUTLET
115
PIPE - FLOW
116
PIPE - RETURN
117
PIPE - EXPANSION VESSEL
118
EXPANSION VESSEL
120
FLOW GROUP MANIFOLD
121 By-Pass Kit
131
WATER PRESSURE TRANSDUCER
135 PRESSURE GAUGE
136 Safety Valve Drain Pipe
203
GAS COCK
204
PIPE - GAS INLET

205
GAS VALVE
206
PIPE - GAS INJECTOR
211
INJECTOR ASSEMBLY
214
VENTURI
215
FAN
217
BURNER
218
GASKET - BURNER
219
SUMP CLEAN OUT COVER
223 FLUE MANIFOLD
224
FLUE MANIFOLD TOP
227
CLAMP RETAINING FLUE TURRET
228
HOSE CONDENSATE INTERNAL
229
SIPHON TRAP
231
CONDENSATE OUTLET CONNECTION
301
CONTROLS BOX FIXINGS HINGE & SPRING
302
PRIMARY PCB*
303
CUI BOARD

504

304
CONTROL THERMISTOR (RETURN)
306
ELECTRODE IGNITION
307
ELECTRODE DETECTION
308
IGNITER UNIT
309
THERMISTOR CONTROL/NO FLOW
313
IGNITION LEAD
314
CONTROL BOX LENS
324
CONTROLS BOX LID
325
CONTROL BOX FRONT
332
FLUE THERMOSTAT
401
HEAT ENGINE
503
WALL MOUNTING BRACKET
504
FRONT PANEL
505
FASCIA
506
BRACKET - GAS VALVE
507
BRACKET - EXPANSION VESSEL

* Note that production boiler PCBs are factory
pre-set to operate for boiler range and output,
but when ordering Primary PCB as a spare, an
additional Boiler Chip Card (BCC) MUST also
be purchased for your specific boiler range and
output.

227

224
503

505

313
218

217

507

309

215

306
211

118

401

308

214

307
136

506

206

113

301

115

131

116

228

205
219
204

304

229

120

110

231
114

303
117

121
105

223

332

108

135

203
104

324

314

BCC
325

302

Keston System - Installation and Servicing

general
unpacking

INSTALLATION

Unpack and check the contents.
A

Pack A Contents
A Boiler
B Hardware Pack Box
C Wall Mounting Plate
D These Installation/Users Instructions
E Wall Mounting Template

(located on internal protective packaging)
F Turret Clamp
G Safety Valve Drain Pipe
H Boiler Guarantee & Registration Pack

D
H
G

Boiler Guarantee

HARDWARE PACK CONTENTS
Gas Valve Pack
1. Pipe - Gas Inlet
2. Washer - Gas (blue)
3. Gas Cock

Gas Valve Pack

2
2

Return Valve Pack

Flue Pack Contents
Flue Adaptor
Air Spigot
Terminals - 2 off
Flue Sleeve
Wall Plate
Wall Seal
Outside Sensor
Screws - 4 off
Wall Plugs - 4 off

Flow Valve Pack

1
1

Flow Valve Pack
1. Pipe CH Flow
2. Washer CH
3. Valve Flow (with gauge)

A
B
C
D
E
F
G
H
J

Return Valve Pack
1. Pipe CH Return
2. Washer CH
3. Valve Return
Accessory Pack
1. Screw (x2)
2. Wallplug (x2)
3. Turret Clamp Screw (X1)

Accessory Pack

3G9945

E
D

7 front panel removal
1
1. Loosen the 2 screws retaining the front panel.

2. Pull the two spring clips downwards to disengage.
3. Pull the front panel forward and upwards to remove.

Keston System - Installation and Servicing

INSTALLATION
8

FLUE SYSTEM

When installing a replacement boiler a new flue system must
be used. DO NOT re-use the existing boiler flue installation.

Design
Individual air supply and flue outlet pipes are used as standard.
The material used for flue outlet &/or air inlet must be
muPVC (PVC-C) to BS 5255 and/or BSEN 1566-1 and BSEN
1329 of an internal diameter of 51mm. (i.e. nominal 50mm
diameter muPVC solvent weld waste pipe).
Marley muPVC (PVC-C) Solvent Weld Waste System
(50mm) and Polypipe System 2000 muPVC (PVC-C) solvent
weld waste (50mm) are the only systems approved for this
application.

The following pipes and fittings are approved:
Polypipe System 2000 muPVC solvent Weld Waste System
(50mm)

Poly Pipe Code
MU 301

4m length muPVC wastepipe 5/225

MU 313

50mm x 45 deg muPVC obtuse bend

MU 314

50mm x 92.5 deg muPVC swept bend

MU 310

50mm muPVC straigh coupling

MU 316

50mm x 92.5 deg muPVC swept pipe

Marley muPVC solvent Weld Waste System (50mm)
Marley Code
50mm x 4m double spigot pipe

KP32

50mm x 45 deg bend

KSC3

50mm straight coupling

KB3

50mm x 88.5 deg bend

KT3

50mm swept tee

FLUE OUTLET

KP 304

continued............

Keston System - Installation and Servicing

INSTALLATION
9

FLUE SYSTEM.... CONT’D

Termination of the flue and air
The flue and air pipes may terminate independently through any
external walls within the same dwelling except on opposing walls,
within the maximum lengths shown in graph below.

TERMINAL POSITIONS

The air pipe must have an elbow and 150mm length of pipe
directed downwards with a termination grill fitted.

Flue
Pipe

Minimum Separation
140mm

Elbow

The air pipe can be situated at the side or beneath the flue pipe to
a minimum dimension of 140mm (see diagram opposite). It must
not be sited above the flue pipe.

Condensing boiler emit a visible plume of water vapour from the
flue terminal, this is normal. It is the responsibility of the installer
to judiciously select a terminal location that does not cause a
nuisance.

Acceptable
range of air
pipe siting

If either the flue or air terminal is below a height of 2m from ground
level a terminal guard must be fitted.

150mm

The flue and air pipes must extend by at least 40mm from the wall
surface.

Air Pipe
Terminal

Maximum lengths

Keston System 30 - Flue & Air Pipe Length

38
34

Air Pipe Length [m]

30
26
22
18
14
10
6
2

Acceptable Operating Area
2

10 12 14 16 18 20 22 24 26 28 30
Flue Pipe Length [m]

Slope
‘Horizontal’ flue outlet pipework MUST slope at least 1.5 degrees (26mm per metre run) downwards towards the boiler. Pipework
can be vertical. Only swept elbows can be used.
Air inlet pipework can be truly horizontal or vertical, or sloping in a downward direction towards the boiler but in each case rain, etc.,
must be prevented from entering the pipe. There must be no troughs in any of the pipework, whether it be air inlet or flue
outlet.

Keston System - Installation and Servicing

FLUE OUTLET

Due to the resistance presented by extended flue length a slight reduction in maximum boiler output will occur where
combined flue and air lengths in excess of 18.0m (50mm muPVC) are used. In such cases the boiler output will be reduced by
0.6% per additional metre.
The maximum lengths of both air inlet pipe and flue outlet pipe, when no bends are used, are as detailed in graph below.
However, each bend used has an equivalent length that must be deducted from the maximum straight length stated in graph
below. Knuckle bends must not be fitted.
A 92.5º swept elbow is equivalent to 1.0m straight length. A 45º bend is equivalent to 0.5m straight length.
It is possible to have variable flue and air lengths as described within the shaded area of graph below.

INSTALLATION
10 Flue Installation Example Keston System 30
4m
1.5º back
to boiler

15.5

34
30

Air Pipe Length [m]

Keston System 30 - Flue & Air Pipe Length

Bracket at
each 1 metre
6m

26
22
18
14
10.15

2m 1.5m

0.15m

1.5º back
to boiler

Acceptable Operating Area
2

10 12 14 16 18 20 22 24 26 28 30
Flue Pipe Length [m]

Calculations
Air
Elbows 2 x 1m = 2m
Straights 6+2+0.15 = 8.15m
Total = 10.15m

Flue
Elbows 3 x 1m = 3m
Straights 4+6+1.5+1 = 12.5m
Total = 15.5m

Overall Flue / Air = 25.65m

Keston System 30 - Flue & Air Pipe Length

38
Sleeve

Air
0.15m

14.5

Air Pipe Length [m]

FLUE OUTLET

11 Flue Installation Example Keston system 30

4m
1.5º back
to boiler

3.5m

1.5m

2m
Bracket every
1 metre
1.5º back
to boiler

2.5m

26
22
18

15.65

14
10
6

Calculations
Air
Flue
4 x 90º elbows
4
3 x 90º elbows
Straight lengths
2
Straight lengths
2
3.5
4
0.15
15.65

3
2.5
1.5
3.5
4
14.5

Acceptable Operating Area
2

10 12 14 16 18 20 22 24 26 28 30
Flue Pipe Length [m]

Overall Flue / Air = 30.15m

Keston System - Installation and Servicing

INSTALLATION
12 Flue Termination Position
Twin Flue Positions

Flue Minimum Spacing

Air Minimum Spacing

A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
L.
M.
N.

Below an opening (1)
Above an opening (1)
Horizontally to an opening (1)
Below gutters, soil pipes or drain pipes
Below eves
Below balcony or car port roof
From a vertical drain pipe or soil pipe
From an internal or external corner or to a boundary alongside the terminal
Above ground, roof or balcony level
From a surface or a boundary facing the terminal
From a terminal facing the terminal
From an opening in the car port into the building
Vertically from a terminal on the same wall
Horizontally from a terminal on the same wall

(1)

An opening here means an openable element, such as a openable window, or a fixed opening such as an air vent. However, in addition, the outlet should not
be nearer than 150mm (fanned draught) to an opening into the building fabric formed for the purpose of accommodating a built in element, such as a window frame.

300 mm
300 mm
300 mm
75 mm
200 mm
200 mm
150 mm
300 mm
300 mm
600 mm
1200 mm
1200 mm
1500 mm
300 mm

12"
12"
12"
3"
8"
8"
6"
12"
12"
24"
48"
48"
60"
12"

50 mm
50 mm
50 mm
75 mm
50 mm
50 mm
50 mm
50 mm
100 mm
100 mm
1200 mm
100 mm
1500 mm
300 mm

2"
2"
2"
3"
2"
2"
2"
2"
4"
4"
48"
4"
60"
12"

The dimensions given in the table above may need to be increased to avoid wall staining and nuisance depending on site conditions.

boundary
D, E

I
B
J

A
L

M
F

boundary

FLUE OUTLET

General Installations
All parts of the system must be constructed in accordance with BS 5440 Part 1, except where specifically mentioned in these
instructions.
All pipe work must be adequately supported.
All joints other than approved push-on or plastic compression connectors must be made and sealed with solvent cement suitable
for muPVC pipes and conforming to BS 6209: 1982.
Consideration must be given to Corgi/Gas Safe bulletin TB200/TB008 regarding flues in voids.
The boiler casing must always be correctly fitted to the boiler when leaving the appliance operational.
External wall faces and any internal faces of cavity walls must be good.

Air Supply
The Keston Combi is a room-sealed appliance and therefore does not require purpose provided ventilation to the boiler room for
combustion air.

Compartment installation
Due to the low casing temperatures generated by the boiler, no compartment ventilation is required. However, the cupboard or
compartment must not be used for storage.

Keston System - Installation and Servicing

INSTALLATION
13 INSTALLING the boiler
Installation of the boiler is straightforward but consideration must be given to access to allow flue and air pipes to be pushed
through walls and ceilings. The order in which the components are installed will depend upon particular site conditions, but in
general it will be easiest and most accurate to install the boiler and then build up the flue outlet and air inlet pipes to the terminal this is the sequence described.

14 wall mounting template
The wall mounting template is located on the internal protective
packaging.
Note.
The template shows the positions of the fixing holes and the
rear flue hole centre for standard installation. Care MUST be
taken to ensure the correct holes are drilled.
1. Tape template into the selected position. Ensure squareness
by hanging a plumbline as shown.
2. If fitting a side flue extend the flue centre line onto the side
wall and measure in 155mm for standard installation.
3. Mark onto the wall the following:
a The wall mounting plate screw positions (choose one from
each group).

b. The position of the flue duct hole (see diagram below).

Note. Mark the centre of the hole as well as the
circumference.
4. Remove the template from the wall.
8

15 preparing the wall

Important.
Ensure that, during the cutting operation, masonry falling
outside of the building does not cause damage or personal
injury.
1. Cut the flue and air holes (preferably with 60mm core bore
tool) ensuring the holes are square to the wall.

Rear flue only
60mm diameter
holes

2. Drill 2 holes with a 7.5mm / 8mm masonry drill and insert
the plastic plugs, provided, for the wall mounting plate.
3. Locate 2 No.14 x 50mm screws in the wall mounting plate
(one at each side, in any of the 3 holes provided at each
side) and screw home.

X
Section
through wall
Note. Check all of the hole
positions before drilling.

3G10030

FLUE OUTLET

3G1037

Keston System - Installation and Servicing

INSTALLATION
16 Fitting the Wall Mounting Plate

17 Mounting the Boiler

Screw the wall mounting plate to the wall using 2 wall plugs
(previously fitted) with the 2 screws provided.

1. Ensure the plastic plug is removed from the CH
connections before mounting the boiler.

Choose one of the 2 sets of slots in left and right bank.
Ensuring that at least one of the screws is fitted into a top slot.

2. Lift the boiler onto the wall mounting plate (refer to the
Introduction section for safe handling advice), locating it
over the two tabs.

Example of fixing

3G9948

Remove all plastic debris and burrs when installing air intake piping.
Plastic fillings caused by cutting muPVC pipe must not be allowed
to be drawn into the combustion air blower. Prevent dust entering
the air intake when cutting on building sites. Blower failure which is
determined to be caused by plastic filings or other debris will not be
covered by guarantee.

•

From outside, complete the two terminations - See Frame
9 Flue System and make good all holes. (Wall sealing
collars are available to make good hole areas on the wall
face (part number C.08.0.00.07.0).

•

Support any pipes whose route could be displaced
either of its own accord or by accident. Any
horizontal run over 1m or vertical runs of any length
must always be supported. Brackets should be
placed at intervals of approximately 1m. Brackets
should be loose enough on the pipe to allow thermal
expansion and contraction movement.

•

Flue pipework through walls MUST be sleeved to
allow thermal expansion and contraction movement.

•

Check all connections for security and re-seal any joints
using solvent cement where soundness may be in doubt.

installing flue and air pipes
Important - When installing the boiler on an existing system a new
flue and air intake system MUST also be installed. You MUST NOT
re-use existing flue or air pipework components.

•

Remove the flue adaptor and air spigot from the flue pack
supplied with the boiler.

•
•

Remove boiler front panel - Frame 38.

•

Fix air spigot to boiler using the 4 M5 screws, see diag. below.
Ensure sponge gasket is in place and not damaged.

•

Insert the flue adaptor into the flue manifold on the top of the
boiler ad secure using the clamp provided in the packaging box,
see diagram below.

•

Measure, cut and check the air and flue pipes to pass to the exit
from the wall(s) or ceiling.

•

Always thoroughly deburr all pipes and most important, remove
shavings from within the pipe.

•

Assemble, using solvent weld cement, the pipework from the
boiler connections to the exit from the first wall/ceiling, (remount
the boiler if removed). When pushing pipe through walls, ensure
grit and dust is not allowed to enter the pipe.
Ensure pipes are fully engaged into sockets and
solvent welded with no leaks.

•

Remove air intake blanking plate by unscrewing 4 x M5 screws
and put to one side, leaving sponge gasket in place.

Note. It is equally important to seal the air inlet with solvent
cement as the flue outlet pipe joints.

Using the same methods drill any further holes (always covering
existing pipework), cut and assemble the pipework.

Keston System - Installation and Servicing

FLUE OUTLET

18 assembly practice

INSTALLATION
19 Fitting the Sleeving
1. Cut hole in wall.
2. Measure wall Thickness
3. Cut sleeve length to match wall thickness & remove burrs.
4. Grout sleeve into wall with flange on external face.
5. Slide flue pipe into sleeve, checking it is free to slide.
6. Slide Flexible wall seal over flue pipe and push centre ring up to sleeve flange when cold.
7. Locate wall plate over flexible wall seal and clamp in place using the raw plug pack.
8. Affix flue terminal
9. During boiler test check that the flue end is free to expand and contract with flexible wall seal.

Flue
Terminal

Flue Pipe

Flue Sleeve

Flue Sleeve Flange
Wall
Plate

FLUE OUTLET

Flexible
Wall
Seal

Keston System - Installation and Servicing

INSTALLATION

149

Condensate
Drain

This appliance is fitted with a siphonic 75mm condensate trap

system that requires filling before operating the appliance for the
1st time or after maintenance.
All condensate pipework should conform to the following:
a. Where a new or replacement boiler is being installed, access to
an internal ‘gravity discharge’ termination should be one of the
main factors considered in determining boiler location.
b. Plastic with push fit or solvent connections.
c. Internal plastic pipe work a minimum of 19mm ID (typically
22mm OD)
d. External plastic pipe must be a minimum of 30mm ID (typically
32 OD) before it passes through the sleeved wall.
e. All horizontal pipe runs, must fall a minimum of 45mm per metre
away from the Boiler.
f. External & unheated pipe work should be kept to a minimum
and insulated with Class “O” waterproof pipe insulation.
g. All installations must be carried out in accordance to the
relevant connection methods as shown in the “Condensate
installation diagrams” & BS6798:2009
h. Pipe work must be installed so that it does not allow spillage
into the dwelling in the event of a blockage (through freezing)
i. All internal burrs should be removed from the pipe work and any
fittings.
In order to minimise the risk of freezing during prolonged very cold
spells, one of the following methods of terminating condensate
drainage pipe should be adopted.
Internal Drain Connections
Wherever possible, the condensate drainage pipe should be routed
to drain by gravity to a suitable internal foul water discharge point
such as an internal soil and vent stack or kitchen or bathroom
waste pipe etc. See Figs 1 and 2.

Figure 1 - Connection of Condensate Drainage Pipe to
Internal Soil & Vent Stack

-
-

For connections to an external soil/vent stack see Fig 4.
Insulation measures as described should be used.
When a rainwater downpipe is used, an air break must be
installed between the condensate drainage pipe and the
downpipe to avoid reverse flow of rainwater into the boiler
should the downpipe become flooded or frozen, see Fig 5.
Where the condensate drain pipe terminates over an open
foul drain or gully, the pipe should terminate below the grating
level, but above water level, to minimise “wind chill” at the open
end. The use of a drain cover (as used to prevent blockage by
leaves) may offer further prevention from wind chill. See Fig 6.
Where the condensate drain pipe terminates in a purpose
designed soak away (see BS 6798) any above ground
condensate drain pipe sections should be run and insulated as
described above. See Fig 7

Unheated Internal Areas
Internal condensate drain pipes run in unheated areas, e.g. lofts
basements and garages, should be treated as external pipe.
Ensure the customer is aware of the effects created by a frozen
condensate and is shown where this information can be found in
the user manual.

Figure 2 - Connection of a Condensate Drainage Pipe
Downstream of a Sink, Basin, Bath or Shower Water Trap to
Internal Soil Vent Stack

Minimum
connection
height up to 3
storeys

Boilers without 75mm sealed
condensate trap must be fitted with
a 75mm trap and visible air break

Sink/basin/
bath or
shower

Min Ø 19mm
Internal pipe

≥ 100
≥ 450

Min Ø 19mm
Internal pipe

The external pipe run should be kept to a minimum using the most
direct and “most vertical” route possible to the discharge point, with
no horizontal sections in which condensate might collect.

Boiler
with 75mm
sealed
condensate
trap

Soil & vent stack

Boiler
with 75mm
sealed
condensate
trap

External Drain Connections
The use of an externally run condensate drainage pipe should
only be considered after exhausting all internal termination options
as described previously. An external system must terminate at a
suitable foul water discharge point or purpose designed soak away.
If an external system is chosen then the following measures must
be adopted:

≥ 100

203

Condensate Pump
Where gravity discharge to an internal termination is not physically
possible or where very long internal pipe runs would be required
to reach a suitable discharge point, a condensate pump of a
specification recommended by the boiler or pump manufacturer
should be used terminating into a suitable internal foul water
discharge point such as an internal soil and vent stack or internal
kitchen or bathroom waste pipe etc. (fig 3).

Internal soil & vent stack

INSTALLATION

20 condensate drain

Boilers without 75mm sealed
condensate trap must be fitted with
a 75mm trap and visible air break

continued . . . . .

Keston System - Installation and Servicing

INSTALLATION

Boiler
with 75mm
sealed
condensate
trap

Min Ø 19mm
Internal pipe

Water/weather
proof insulation

Min Ø 30mm
Internal pipe

Boiler
with 75mm
sealed
condensate
trap

Water/
weather proof
insulation

Min Ø 19mm
Internal pipe

External air
break
Air gap
Terminated
and cut at 45º
43mm 90º male/
female bend

68mm Ø PVCU
Strap on fitting

Visible air break
at plug hole

Min Ø 19mm
Internal pipe
Sink, basin, bath or
shower with integral
overflow and 75mm trap

Water/
weather proof
insulation

Minimum 30mm
internal pipe

45º pipe
termination

Figure 7 - Connection of a Condensate Drainage Pipe to an
External Purpose Made Soak Away.

Boiler
with 75mm
sealed
condensate
trap
Min Ø 30mm
Internal pipe

Max 3m external
pipework

Boilers without 75mm sealed
condensate trap must be fitted with
a 75mm trap and visible air break

≥ 300

≥ 25

Min Ø 19mm
Internal pipe

Water/Weather
proof insulation

FLUE OUTLET

Min Ø 30mm
Internal pipe

Boiler
with 75mm
sealed
condensate
trap
combined foul/
rain water drain

Minimum
connection
height up to 3
storeys

Figure 6 - Connection of Condensate Drainage Pipe
Upstream of a Sink, Basin, Bath or Shower Waste Trap to
External Drain, Gulley or Ranwater Hopper

Figure 5 - Connection of a Condensate Drainage Pipe to an
External Rainwater Downpipe (only combined foul/rainwater
drain)

Boilers without 75mm sealed
condensate trap must be fitted with
a 75mm trap and visible air break

≥ 100

Condensate pump
(Install in accordance with manufacturers instructions)

≥ 450

Min Ø 19mm
Internal pipe

≥ 25 Below grate

Visible air break

Boiler
with 75mm
sealed
condensate
trap

Figure 4 - Connection of condensate Drainage Pipe to
External Soil & Vent Stack

Soil & vent stack

Figure 3 - Connection of a Condensate Pump Typical
Method (see manufacturers detailed instructions)

INSTALLATION

21 Condensate drain - Cont’d.......

≥ 500

Limestone
chippings

2 rows of three Ø12mm holes
25mm centres, 50mm from
the bottom of the tube, facing
away from the house

Keston System - Installation and Servicing

INSTALLATION
INSTALLATION

22 connections & Filling
NOTES.
Ensure all boss blanking plugs are removed before connecting hardware. Each valve must be fitted to the correct boss as shown
in the picture.
Ensure each union is fitted with fibre seals provided. Do not subject any of the isolating valves to heat as the seals may
be damaged.

WATER CONNECTIONS CH

1. Connect the CH flow service valve provided in the hardware
pack to the threaded boss connection provided at the lower
rear of the boiler.
2. Connect the CH return valve.
3. If connecting the boiler to heating loads in excess of
60,000 Btu/h, connecting flow and return heating systems
pipework must be sized in 28mm diameter at the point of
pipe connection to the boiler tails. Use 22mm x 28mm pipe
adaptors as appropriate.

GAS CONNECTION

IMPORTANT.
The gas service cock is sealed with a non-metallic
blue fibre washer, which must not be overheated when making
capillary connections. Refer to Frame 1 for details of the position of
the gas connection.
For additional gas supply information refer to “Gas Supply” on page 8.

FILLING
Important - when filling:
A. Ensure the dust cap on air vent
located at the rear of the pump
chamber is slightly unscrewed.
B. When filling, there may be a slight
water leak from the air vent therefore
electrical connections should be
Dust Cap
protected.
1. Ensure that the CH isolating
handles are open.
2. Fill and vent the system. Refer
to Frame 2 for filling and setting
pressure procedure.
3. Check for water
soundness.

safety valve Drain

Safety Valve
Drain Connection
15mm elbow
or fittings
(not supplied)

Safety Valve
Drain Pipe

Note that all isolation handles are
shown in the open position.

Black
Handle
CH Flow
205552-10119

Yellow
Handle

Gas
Supply

Safety
Drain
Valve

Black
Handle
CH Return

Keston System - Installation and Servicing

FLUE OUTLET

3G9705

The safety valve connection, located at the bottom right-hand side of the boiler,
comprises a 15mm diameter stub pipe.
The discharge pipe should be positioned so that the discharge of water or steam
cannot create a hazard to the occupants of the premises or damage the electrical
components and wiring.
A purpose made safety valve drain pipe is provided with the boiler to allow safe
discharge through a wall to the outside of the building. This is particularly relevant to
‘high rise’ installations but can be used for all installations.

INSTALLATION

INSTALLATION
23 electrical connections
Warning. This appliance must be earthed.
A mains supply of 230Vac ~ 50 Hz is required.
The fuse rating should be 3A. All external controls and wiring
must be suitable for mains voltage.
Wiring external to the boiler MUST be in accordance with the
current I.E.E. (BS.7671) Wiring Regulations and any local
regulations.

Wiring should be 3 core PVC insulated cable, not less than
0.75mm2 (24 x 0.2mm), and to BS 6500 Table 16. For IE
reference should be made to the current ETCI rules for
electrical installations.
Connection must be made in a way that allows complete
isolation of the electrical supply such as a double pole switch
having a 3mm (1/8”) contact separation in both poles. The
means of isolation must be accessible to the user after
installation.

24 internal wiring
The Keston System boiler comes pre-fitted with 1.8m of mains cable. This must be
connected to a permanent live supply and NOT switched by thermostats/programmers.
For installers wishing to change this cable refer to Frame 26.
Connecting the Switched Live to the Boiler
1.
2.
3.
4.
5.

Consult the Y Plan and S Plan diagrams below.
Isolate the mains supply to the boiler
Remove the front panel. Refer to Frame 7.
Swing the control box down into the servicing position.
Route incoming cable through a grommet in the bottom panel (note that the
grommets are “blind” and will require puncturing) and secure using the clamp and
screws provided in the hardware pack.
6. Connect the switched live to the terminal block as shown.

Frost thermostat - Wiring
If parts of the system are
vulnerable to freezing or the
programmer is likely to be left off
during cold weather, a frost stat
should be fitted in conjunction with
a pipe thermostat.

Keston System BOILER, Y PLAN SYSTEM without Weather Compensation
L

E
b
g/y

FUSED
SPUR

g
R/S

Y PLAN
VALVE

C/S

BOILER
L

TIMER

CH R/S HW HW C/S
ON ON ON OFF ON

CH ON
HW ON
HW OFF
3G10022

See overleaf for S Plan System..................

Keston System - Installation and Servicing

INSTALLATION
INSTALLATION

25 internal wiring Cont’d.......
Keston System BOILER, S PLAN SYSTEM without weather compensation
g

HW
S PLAN
VALVE

b
L

g/y

CH
S PLAN
VALVE

g/y

FUSED
SPUR

br
R/S

C/S

TIMER

BOILER
L

CH R/S HW HW C/S
ON ON ON OFF ON

CH ON
HW ON
3G10023

26 rEPLACING PRE-FITTED MAINS CABLE
If it is necessary to use an alternative mains cable to the one pre-fitted
then use the following guide.
Replacement wiring should comply with notes in Frame 23.
1. Isolate the mains supply to the boiler.
2. Remove the front panel. Refer to Frame 7.
3. Swing the control box down into the service position. Refer to frame
46.
4. Remove the live, neutral and earth wires from the terminal block.
5. Loosen the cable clamp and withdraw the mains cable.
6. Route replacement cable back through the cable clamp and grommet
and re-tighten to provide cord anchorage.
7. Connect the live, neutral and earth wires to the terminal strip. When
making the mains electrical connections to the boiler it is important
that the wires are prepared in such a way that the earth conductor
is longer than the current carrying conductors, such that if the cord
anchorage should slip, the current carrying conductors become taut
before the earthing conductor.
8. Swing the control box back up into the operating position and re-fit the
front panel ensuring a good seal is made.

Keston System - Installation and Servicing

INSTALLATION

INSTALLATION
27 FITTING THE WEATHER COMPENSATION KIT - supplied as standard
This kit provides the facility to apply outside air temperature control to the boiler water
flow temperature which provides energy savings. The outside sensor provided measures
outside air temperature and sends a signal to the boiler, which adjusts the maximum boiler
flow temperature in response. If outside air temperature is greater than the system design
temperature, the boiler flow temperature is reduced providing running cost savings. The boiler
will operate in the condensing mode more frequently increasing savings.
Once the sensor is fitted it is automatically detected.

Kit Contents
A. Outside Air Sensor
A

The sensor operation may be configured by adjustment of the boiler operating parameters, if
necessary.

fitting the kit
Fitting the sensor

3G10011

The air sensor should be located on an external wall of the building to be heated. Fix the sensor
to a north/north-east facing wall to avoid direct radiation from the sun. The air sensor should be
located to avoid any heating effect from the boiler flue.
To fix the air sensor to the wall, unscrew the sensor box plastic cover and screw/plug the sensor body to the wall.

Wire a twin core 0.5mm2 cable from the sensor to the boiler through an RH grommet located on the underside of the boiler. Cable
length between sensor and boiler should be no greater than 20m. Note that this connection is safety extra low voltage. It is not
necessary for the person carrying out the wiring to be approved to Part P of the Building Regulations.
Avoid running this cable alongside mains voltage cables.
The signal DHW OFF from the system wiring centre and a common neutral must be wired into the appliance through another
RH grommet located on the underside of the boiler. The wire shall be suitable for mains voltages and be 0.5mm2 twin core with
sheath (Double insulated) construction according to current wiring regulations.
Fitting the kit
1. Isolate the electricity supply to the boiler and system
controls.

Outside
sensor
wiring

Wiring
Centre
Connections

2. Remove the boiler front panel (refer to boiler installation
instructions).
3. Hinge down the control box and remove the 2 screws
retaining the control box cover, release the 4 retaining clips
(refer to boiler installation instructions).
Wiring the kit
1. Carefully pierce a grommet using a suitably sized
screwdriver.
2. Pass the wire from the outside sensor through this
grommet, strip and prepare the ends for termination.
3. Wire the outside sensor into the 2 LHS terminals of the
terminal block as shown and labelled.
4. Secure the wire with one bar clamp and two screws,
ensure that there is only a small loop between the bar
clamp and the grommet, and that the wire can not be
trapped.
5. Carefully pierce a separate grommet using a suitably sized screwdriver.
6. Pass the 2 core sheathed wire from the wiring centre through this grommet and strip back the outer sheath, strip and prepare the
ends for termination.
7. Wire the switched live signal, DHW OFF, from the wiring centre along with the permanent neutral into the 2 RHS terminals of the
terminal block
8. Secure the wire with the other bar clamp and two screws, ensure that there is only a small loop between the bar clamp and the
grommet, and that the wire can not be trapped.
9. Re-assemble in reverse order.

Keston System - Installation and Servicing

INSTALLATION
INSTALLATION

28 FITTING THE WEATHER COMPENSATION KIT - supplied as standard
Key
b - blue
br - brown
g - green
g/y - green/yellow
o - orange
w - white

Keston System Boiler with Y Plan System & Weather Compensation Kit
L

E
b
g/y

FUSED
SPUR

Y PLAN
VALVE

C/S

R/S

BOILER
L

CH R/S HW HW C/S
ON ON ON OFF ON

OUTSIDE
SENSOR
L

CH ON

TIMER

HW ON

‘HW OFF’
Wiring
Centre

HW OFF

Keston System Boiler with S Plan System & Weather Compensation Kit

HW
S PLAN
VALVE

b
L

g/y

CH
S PLAN
VALVE

g/y

FUSED
SPUR

br
R/S

C/S

br
o

BOILER
L
L

TIMER

CH R/S HW HW C/S
ON ON ON OFF ON

CH ON

OUTSIDE
SENSOR

HW ON
HW OFF

NOTE. Changes to cylinder stat connections and addition of HW OFF from timer.

Keston System - Installation and Servicing

‘HW OFF’
Wiring
Centre

29 FITTING THE WEATHER COMPENSATION KIT - supplied as standard

CH Operation
The On and Off time control of central heating should be controlled
by a separate timer.
During programmed On times the Central Heating Radiator Flow
Temperature is controlled by the boiler relative to the Outside
Temperature as shown in the diagram.
The Room temperature can be adjusted using the Central Heating
Temperature Control Knob on the boiler as follows. Essentially
rotating the knob clockwise increases the room temperature and
rotating the knob anti-clockwise decreases the room temperature.

Weather Compensation Control / Room Setpoint = +20ºC
CH Temperature Setpoint [C]

INSTALLATION

Heating slope

If the Central Heating Temperature Control Knob is rotated
fully clockwise then for an Outside Temperature of 15°C a Flow
20
Temperature of 40°C will be provided. For an Outside Temperature
of 0°C a Flow Temperature of 78°C will be provided with the
relationship varying lineally in between these 2 points (line on the graph 2.5)

2.5

2.2 2.0

1.8

1.6

1.4

1.2

1.0

100
90
80
70
60
50
40
30

-10

-20

-30

20
-40

Outside Temperature [ºC]

If the Central Heating Temperature Control Knob is in its mid position then for an Outside Temperature of 15°C a Flow
Temperature of 36°C will be provided. For an Outside Temperature of 0°C a Flow Temperature of 65°C will be provided with the
relationship varying lineally in between these 2 points (line on the graph between 1.6 and 1.8)
If the Central Heating Temperature Control Knob is rotated fully anti-clockwise then for an Outside Temperature of 15°C a Flow
Temperature of 30°C will be provided. For an Outside Temperature of 0°C a Flow Temperature of 44°C will be provided with the
relationship varying lineally in between these 2 points (line on the graph 1.0)

DHW Operation
When the system is in a timed on period for DHW and the tank stat is not satisfied, a call for heat will be generated on the
switched live into the boiler.
At the same time, the HW OFF signal will not be present, this will release the Relay and place a short across the DHW thermistor
input on the Main Control board, this will ensure that Weather Compensation adjustment is ignored at this time. The set point will
be fixed at 70 degrees.
The demand is indicated on the display by a ‘C’ and the burner on LED as appropriate.

30 external electrical controls
Wiring External to the Boiler
The fuse rating should be 3A.
Wiring external to the boiler MUST be in accordance with the current I.E.E. (BS.7671) Wiring Regulations and any local
regulations.
Frost Protection
If parts of the pipework run outside the house or if the boiler will be left off for more than a day or so then a frost thermostat should
be wired into the system.
The frost thermostat should be sited in a cold place but where it can sense heat from the system.
Note. If the boiler is installed in a garage it may be necessary to fit a pipe thermostat, preferably on the return pipework.

Keston System - Installation and Servicing

Water
Pressure
Sensor

Fan

y/g
b br

Flow
Thermistor

bk
N sL

X3
1

y/g

Spark
Electrode

Flame
Sensor
Electrode

PCB

HW Outside
off Sensor

Relay

X7A
2

Snubber

Service
Connector

Return
Thermistor

X7B

11 10 9 8 7 6 5 4 3 2 1 6 5 4 3 2 1 4 3 2 1 2

KEY
b - blue
bk - black
br - brown
r
- red
p - pink
y - yellow
w - white
y/g - yellow/green
g - grey
or - orange
v - violet

y/g

X2B

y/g

Flue
Thermostat

X1D
3

Chassis
Earth

Gas
Valve

y/g

X2A
3

Spark
Generator

Pump

y/g br

X1C
3

X1B
1

y/g bk

X1A
2

31 wiring diagram
INSTALLATION

Fused
at 4AT

INSTALLATION

INSTALLATION
32 Commissioning and Testing
B. Gas Installation

A. Electrical Installation
1. Checks to ensure electrical safety should be carried out by a
competent person.
2. Always carry out the preliminary electrical system checks,
i.e. earth continuity, polarity, resistance to earth and short
circuit, using a suitable test meter.
3. After wiring the boiler, all grommets in the bottom panel
MUST be in place to ensure that the boiler case sealing is
maintained.

1. The whole of the gas installation, including the meter,
should be inspected and tested for tightness and purged in
accordance with the recommendations of BS. 6891.
In IE refer to IS.813:2002.
2. Purge air from the gas installation by the approved methods
only.

WARNING. Whilst effecting the required gas tightness test and purging air from the gas installation,
open all windows and doors, extinguish naked lights and do not smoke.

General
Please Note: The combustion for this appliance has
been checked, adjusted and preset at the factory for
operation on the gas type defined on the appliance
data plate. No measurement of the combustion is
necessary. Do not adjust the air/gas ratio valve.
Having checked:
- That the boiler has been installed in accordance
with these instructions.
- The integrity of the flue system and the flue seals,
as described in the Flue Installation section.
Proceed to put the boiler into operation as follows:

Check the operational (working) gas
inlet pressure
Set up the boiler to operate at maximum rate.
With the boiler operating in the
maximum rate condition check
that the operational (working)
gas pressure at the inlet gas
pressure test point complies with
the requirements - refer to “Gas
Supply” on page 8.

Gas
Supply

Ensure that this inlet pressure
can be obtained with all other
gas appliances in the property
working.

205552-10118

Gas Pressure
Test Point

As part of the commissioning process, the combustion of this appliance must be checked
and the Benchmark Checklist completed. A flow chart to assist is provided on page 61.

ATTENTION !

IT IS A CONDITION OF THE MANUFACTURERS WARRANTY THAT THE
BENCHMARK COMMISSIONING CHECKLIST IS FULLY COMPLETED
AND LEFT WITH THE APPLIANCE

Keston System - Installation and Servicing

INSTALLATION
INSTALLATION

33 initial lighting
Legend
A. CH temperature control
B. Mode Control Knob
C. Boiler Status
D. Burner ‘on’ indicator
E. CH Flow Isolating Valve
F. Pressure Gauge
G. Gas Inlet Pressure Test Point
H. Gas Service Cock
J. CH Return Isolating Valve
K. Drain Valve

F
E

Drain
Valve

CH Flow

10121

Note. Valves shown are in the open position.

Safety
Drain
Valve

Gas Supply

H
G

CH Return

1. Check that the system has been filled and that the boiler is not Important
airlocked. Ensure the automatic air vent cap is open. Refer to The gas input to the burner is regulated by the gas
Frame 22.
valve according to the air flow produced by the fan.
It is not user-adjustable. Any interference to sealed
Note.
settings on the gas valve will adversely affect operation
It is important the burner is not operated before the system is fully
and render our warranty void.
vented of air. If it is necessary to operate the appliance pump to
assist venting of the air this must be done with the gas service cock For additional gas supply information refer to “Gas Supply”
turned off.
on page 8.
2. Refit the boiler front panel. Refer to Frame 38.
3. Check that the drain valve (K) is closed and that the CH isolating
valve (E and J) are OPEN.
4. Check that the electrical supply is OFF.
5. Check that the boiler mode control knob (B) is off.
6. Check that the gas service cock (H) is OPEN.
7. Slacken the screw in the inlet pressure test point (G) and connect
a gas pressure gauge via a flexible tube.
8. Switch the electricity supply ON and check all external controls
are calling for heat.
Central Heating
9. Set the CH temp control (A) to max and turn the mode control knob
(B) to ON. The boiler control should now go through its ignition
sequence until the burner is established.
10. If the boiler does not light after 5 attempts the boiler will lock out
constantly. Reset the boiler (Refer to
and display fault code
Frame 37). The boiler will repeat its ignition sequence. If reset
will be shown. If power
occurs 5 times within 15 minutes then
is removed this will be reset.

When the burner is established the BLUE ‘Burner On’ neon (D)
will be illuminated, the LED display (C) will show status .

11. Ensure that with the boiler operating the dynamic gas pressure
is able to obtain maximum output. Refer to Table 2.

Keston System - Installation and Servicing

THE DISPLAY
The user control has one neon and one display to inform
the user about the status. The display will show the status
of the boiler. The neon will show the status of the flame.
If no flame is detected the neon is off. When the flame is
detected the neon will be lit permanently.
Below is a list with display function in normal operation.
Standby, no demand for heat present.
Boiler is active for central heating or hot water.
Boiler is active for boiler frost protection.
Boiler is in lockout for a specific error. Display will be
blinking, alternating with a number or letter to show
which error is detected.
Boiler has a fault for a specific error. Display will be
blinking, alternating with a number or letter to show
which error is detected.
Note: Boiler frost protection - boiler fires if temperature is
below 5 degrees C.

Note. The boiler incorporates a fan overrun cycle which
MUST NOT be prematurely interrupted by isolation of the
mains electricity supply.

INSTALLATION

INSTALLATION
34 general checks

Make the following checks for correct operation:

Central Heating (CH) mode
1. Ensure that the CH external controls are
calling for heat.
The display should read:

2. Check the boiler gas rate when the boiler is
at full output.
Check at the gas meter, with no other
appliance in use. Refer to Table 2 for gas
rate.
3. Set the central heating external controls
to OFF. The burner should go off and the
pump continue to run for 4 minutes
The display should read:
4. Check the correct operation of the timer
and all other system controls. Operate
each control separately and check that the
main burner responds.

Water circulation system
1. With the system COLD, check that the initial pressure is correct to the
system design requirements.
For pre-pressurised systems, this should be 1.0 bar.
2. With the system HOT, examine all water connections for soundness. The system
pressure will increase with temperature rise but should not exceed 2.5 bar.
3. With the system still hot, turn off the gas, water and electricity supplies to the
boiler and drain down to complete the flushing process.
Note: A flushing solution should be used during the flushing procedure.
Flushing solutions: Fernox Superfloc, Sentinel X300 (new systems) or
X400 (existing systems). Refer to Frame 4.
4. Refill and vent the system, add inhibitor (see Frame 4), clear all air locks and
again check for water soundness.
5. Reset the system initial pressure to the design requirement.
6. Balance the system. Refer to Frame 3.
7. Check the condensate drain for leaks and check that it is discharging correctly.
8. Finally, set the controls to the User’s requirements.
Note: The pump will operate briefly as a self-check once every 24 hours in the
absence of any system demand.

Water temperatures
Temperatures can be selected using the
CH temperature control (A)

35 RESET PROCEDURE
Legend

Knob Setting

CH Flow Temp ºC (ºF)

Max

80 (176)

Min

30 (86)

To reset boiler, turn the mode control knob (B) to reset position and immediately turn
knob back to required setting. The boiler will repeat the ignition sequence.

A. CH temperature control
B. Mode Control Knob
C. Boiler Status
D. Burner ‘on’ indicator
A

36 HANDING OVER
After completing installation and commissioning of the system the installer should hand over to the householder by the following actions:

1. Hand the User Instructions to the householder and explain his/
her responsibilities under the relevant national regulations.
2. Explain and demonstrate lighting and shut down procedures.
3. The operation of the boiler and the use and adjustment of all
system controls should be fully explained to the householder,
to ensure the greatest possible fuel economy consistent with
the household requirements of both heating and hot water
consumption.
Advise the User of the precautions necessary to prevent damage
to the system and the building, in the event of the system
remaining inoperative during frosty conditions.
4. Explain the function and the use of the boiler heating controls.
5. Explain the function of the boiler fault mode.
Emphasise that if a fault is indicated refer to “Fault Codes” in the
User Guide.
6. Explain and demonstrate the function of time and temperature
controls, radiator valves etc., for economic use of the system.
7. If a timer is fitted draw attention to the timer Users Instructions
and hand them to the householder.

8. Loss of system water pressure
Explain that the dial underneath the boiler indicates the central
heating system pressure and that if the normal COLD pressure
of the system is seen to decrease over a period of time then a
water leak is indicated. Explain the re-pressurising procedure
and if unable to re-pressurise or if the pressure continues to drop
a registered local heating installer should be consulted.
9. Explain Boiler reset procedure.
10. After installation and commissioning please complete the
Benchmark Commissioning Checklist before handover to the
customer. For IE, its is necessary to complete a “Declaration of
Conformity” to indicate compliance to I.S. 813:2002.
Important
11. A comprehensive service should be carried out ANNUALLY.
Stress the importance of regular servicing by a Gas Safe
Registered Engineer. In IE servicing work must be carried out by
a Registered Gas Installer (RGII).
12. Inform the householder of the guarantee/registration found within
the envelope pack and the requirement to register it to receive
the full benefit of the warranty.

Keston System - Installation and Servicing

SERVICING
37 servicing schedule
For the very latest copy of literature for specification & maintenance practices, visit our website www.keston.co.uk, where you will
be able to download the relevant information. .
Warning. Always turn off the gas supply at the gas service cock, and switch OFF and disconnect the electricity
supply to the appliance before servicing.
Combustion testing must be carried out by a competent person using a combustion analyser conforming to BS7927.
To ensure the continued safe and efficient operation of the appliance it is recommended that it is checked at regular intervals and
serviced as necessary. The frequency of servicing will depend upon the installation condition and usage but should be carried out
at least annually.
It is the law that any service work must be carried out by a Gas Safe Registered Engineer. In IE service work must be carried out
by a Registered Gas Installer (RGII).
1. Light the boiler and carry out a pre-service check, noting
any operational faults.
2. Check the flue terminal (and terminal guard if fitted) is
undamaged and clear of any obstruction.
3. Check all water and gas joints for signs of leakage.
Remake any suspect joints ensuring a gas tightness
check is carried out if applicable and the water system is
correctly refilled, vented and re-pressurised.

CLEANING PROCEDURE

Note. In order to carry out either servicing or replacement of
components the boiler front panel must be removed.
Refer to Frame 38.
1. Clean the main burner. Refer to Frame 40.
2. Clean the heat exchanger & condensate trap/siphon.
Refer to Frames 42 & 41.
3. Check the main injector for blockage or damage. Refer to
Frame 46.
4. Check that the flue terminal is unobstructed and that the
flue system is sealed correctly.
The cleaning procedures are covered more fully in Frames
40-44 and must be carried out in sequence.
Important.
6. After completing the servicing or exchange of components
always test for gas tightness.

General
Please Note: During routine servicing, and after any maintenance
or change of part of the combustion circuit, the following must be
checked:
- The integrity of the flue system and the flue seals,
- The integrity of the boiler combustion circuit and the relevant
seals
- The operational (working) gas inlet pressure at maximum rate.
- The gas rate
- The combustion performance.

Competence to carry out the check of
combustion performance
Please Note:
BS 6798:2009 Specification for installation and
maintenance of gas-fired boilers of rated input not exceeding
70kW net advises that:
- The person carrying out a combustion measurement should
have been assessed as competent in the use of a flue gas
analyser and the interpretation of the results.
- The flue gas analyser used should be one meeting the
requirements of BS7927 or BS-EN50379-3 and be calibrated
in accordance with the analyser manufacturers requirements,
and

SERVICING

INSPECTION

- Competence can be demonstrated by satisfactory completion
of the CPA1 ACS assessment, which covers the use of
electronic portable combustion gas analysers in accordance
with BS7967, Parts 1 to 4.

7. When work is complete the front panel MUST be correctly
refitted, ensuring that a good seal is made.

Do not operate the boiler if the front panel
is not fitted.
8. If, for any reason, the condensate trap/siphon has been
removed ensure the trap is refilled with water before
reassembling.
9. Check the gas consumption.

Flue
sampling
point

10. Check combustion by connecting the flue gas analayser
to the flue gas sampling point as shown in the diagram
and measure CO & CO2.

If the CO/CO2 ratio is greater than 0.004 AND the integrity
of the complete flue system and combustion circuit seals
have been verified and the inlet gas pressure (and gas
rate) have been verified, then contact Keston.

11. Complete the service section in the Benchmark
Commissioning Checklist.

Keston System - Installation and Servicing

SERVICING
38 boiler front panel removal / Replacement
1

REMOVAL
1. Loosen the two screws retaining the front panel.

2. Pull the two spring clips down to disengage and pull panel
forward and upward and remove.
REPLACEMENT
3. Hook the panel onto the top retaining clips.
4. Push the panel until the 2 bottom spring clips engage
ensuring the 4 control knobs line up with the holes in the
front panel.
5. Re-tighten the two retaining screws.

Servicing

view from bottom of boiler

view from top of boiler

39 fan and venturi assembly removal and cleaning
1. Disconnect the electrical leads from the fan.
2. Undo the gas pipe union connection to the
injector housing.

3. Remove the extended nut on the fan
mounting bracket.
4. Lift off fan and venturi assembly.
5. Inspect the injector for blockage or damage.
6. Inspect fan outlet sealing gasket and
replace if necessary.
5

Injector

Keston System - Installation and Servicing

SERVICING
40 burner removal and cleaning
1. Ensure the sump is fully drained

2. Undo the two screws and remove the sump cover retaining the lower
flue manifold.

3. Lift the manifold to clear the bottom sealing gasket and remove
manifold.
4. Remove the 2 burner front fixing screws and loosen the 2 rear
extended nuts by at least ten turns.
5. Lift off the burner from the combustion chamber. To facilitate the
removal angle the burner as shown.
Important
The burner head is a ceramic plaque construction. Care must be
taken to ensure that the burner is not placed down upon
its face as this may cause damage to the ceramic.

6. Brush off any deposits that may be on the ceramic with a
SOFT brush.

servicing

7. Inspect the sealing gasket around the burner for any
signs of damage. Replace as necessary.

41 cleaning the condensate Trap/Siphon
1. Pull off the rubber pipe at the sump drain.

4. Clean siphon with water.

2. Disconnect the condensate drain pipe.

5. Re-assemble in reverse order.

3. Turn the siphon clockwise to disengage and lift to
remove.

B When re-assembling ensure the trap is full of water.

Note. Keep siphon upright when removing
2

Keston System - Installation and Servicing

SERVICING
42 cleaning the heat exchanger
Note: Ensure the condensate trap/siphon
is fully drained before cleaning. Refer to
Frame 55.

1
Ignition Electrode

Flame Detection

1. Remove ignition and flame detection
electrodes. Refer to Frames 51 & 52.
2. It is advisable to replace the sump cover
prior to the water flush process.
3. Thoroughly flush the heat exchanger
by pouring water into the top of the
combustion chamber ensuring the full top
area is covered.
4. Remove the sump cover and clean loose
deposits from the sump.
3

5. Inspect the ignition and detection
electrodes. Ensure that they are clean
and in good condition - replace if
necessary.

Servicing

6. Re-fit the ignition and flame detection
electrodes, ensuring that both earth tabs
are fitted to ignition electrode.
7. Check that the ignition and detection gaps
are correct. Refer to Frames 51 & 52.

43 reassembly
Reassemble the boiler in the following order:
1. Ensure that the condensate trap/siphon is full of water.
2. Refit the burner ensuring the sealing gasket is correctly
positioned and free from damage (tighten the 4 fixing screws
in the sequence shown below).
3. Refit the fan / venturi assembly ensuring the retaining tabs
are correctly positioned and the sealing gasket is correctly
positioned and free from damage.

7. Refit the boiler front panel.
Important. Ensure that the boiler front panel is
correctly fitted and that a good seal is made.
8. Swing the control box back into its working position and
secure.
9. Turn on the gas supply at the gas service cock.

4. Reconnect the fan electrical leads.

10. Reconnect the electrical supply.

5. Remove the sump cover and refit the lower flue manifold as
shown.

11. Check the operation of the boiler. refer to Frame 32-34

6. Refit the sump cover.
4

Keston System - Installation and Servicing

SERVICING
44 replacement of components
General

After replacing ANY component check operation of the
boiler, including gas soundness, gas rate and combustion
test.

When replacing ANY component
1. Isolate the electricity supply.

Important.
When work is complete, the front panel must be correctly
refitted - ensuring that a good seal is made.

2. Turn off the gas supply.
3. Remove the boiler front panel. Refer to Frame 38.

Notes.
1. In order to assist fault finding, the control panel has
an LED diagnostic display. The key to boiler fault
conditions is shown in Frame 67.

4. Release the retaining clip and swing the control box down
into its servicing position.

servicing

2. In order to replace components in Frames 58-64 it is
necessary to drain the boiler. Refer to Frame 57.

THE BOILER MUST NOT BE OPERATED without THE FRONT PANEL FITTED

45 fan replacement

Retaining Tabs
2

1. Refer to Frame 44.
2. Disconnect the electrical leads from the fan.
3. Undo the gas pipe union connection to the
injector housing.
4. Remove the extended nut retaining the fan
mounting bracket.

5. Lift and remove the fan and venturi assembly.
6. Remove the screw and twist venturi anticlockwise to remove venturi assembly, noting
the orientation of the venturi in relation to the
fan body.

7. Transfer the venturi assembly to the new fan,
replacing the ‘o’ ring if evidence of damage or
deterioration is visible.
8. Fit the new fan / venturi assembly ensuring the
retaining tabs are correctly positioned and the
fan outlet sealing gasket is correctly positioned
and free from damage. Refit the extended nut.
9. Reassemble the boiler in reverse order, taking
care not to overtighten the screw on the fan
mounting bracket.

10. Check the operation of the boiler. Refer to
Frames 32-34.

Keston System - Installation and Servicing

SERVICING
46 Burner injector replacement
1. Refer to Frame 44.

2. Disconnect the electrical leads from the fan.
3. Undo the gas pipe union connection to the
injector housing.
4. Loosen the screw retaining the fan mounting
bracket.
5. Lift and remove the fan and venturi assembly.
6. Remove the 2 injector housing screws.
7. Withdraw the injector housing.

8. Fit the new injector housing complete with
injector.

Servicing

9. Reassemble in reverse order, ensuring that the
new gas seal supplied is located correctly in the
injector housing.
10. Check operation of the boiler. Refer to Frames
32-34.

47 burner REPLACEMENT
1. See Frame 40.
2. Refer to Frame 44.
3. Undo the two screws and remove the sump cover.

4
3

4. Lift the manifold to clear the bottom sealing gasket and remove
manifold.
5. Remove the 2 front fixing screws and loosen the 2 rear extended
nuts.
6. Lift off the burner from the combustion chamber. To facilitate the
removal angle the burner as shown.
7. Fit the new burner, replacing any damaged or deteriorating sealing
gasket.
8. Reassemble in reverse order. Refer to Frame 43.
9. Check the operation of the boiler. Refer to Frames 32-34.

Keston System - Installation and Servicing

SERVICING
48 return thermistor reNEWAL
1. Refer to Frame 44.
2. Unclip the return thermistor from the return pipe and withdraw it from the
boiler.
3. Disconnect the electrical leads from the thermistor.
4. Reconnect the electrical lead to the new thermistor and reassemble in
reverse order, ensuring that the thermistor is securely fitted to the pipe on the
thermistor locator tab as shown.
6. Check the operation of the boiler. Refer to Frames 32-34.

4
Thermistor Locator Tab
(with thermistor fitted)

servicing

49 flue thermostat replacement
1. Refer to Frame 43.
2. Undo the two screws and remove the
sump cover plate.
3. Disconnect the two flag terminals
from the flue thermostat.
4. Lift the manifold to clear the bottom
sealing gasket and remove manifold.
.
5. Unscrew the two M3.5 screws
that connect the thermostat to the
manifold.
6. Replace thermostat with new part
and then refit the two screws,
remembering to fit rubber gasket and
sealing clamp.

Flue Thermostat

Keston System - Installation and Servicing

SERVICING
50 ignition electrode replacement
1. Refer to Frame 44.
2. Remove the burner. Refer to Frame 47.
3. Unplug the ignition lead from the electrode.

Ignition Electrode

4. Remove the earth lead from the ignition
electrode.
5. Remove the 2 screws holding the ignition
electrode to the combustion chamber.
6. Remove the electrode.
7. Fit the new ignition electrode, using the
new gasket supplied. Check dimensions as
shown.
8. Reassemble in reverse order.

Servicing

9. Check the operation of the boiler. Refer to
Frames 32-34.

ge
ed
t
h
aig
Str

Spark Gap
3.5mm

51 flame detection electrode replacement
1. Refer to Frame 44.
2. Remove the burner. Refer to Frame 47.
3. Unplug the flame detection lead from the
electrode.

Flame Detection Electrode

4. Remove the 2 screws retaining the detection
electrode.
5. Remove the electrode.
6. Fit the new flame detection electrode, using the
new gasket supplied.
7. Reassemble in reverse order.
8. Check the operation of the boiler. Refer to
Frames 32-34.

e
dg
te
h
aig
Str

m
2.5

Keston System - Installation and Servicing

SERVICING
52 Spark generator replacement
1. Refer to Frame 44.
2. Disconnect the leads from the spark
generator.
3. Remove the M5 screws securing the
spark generator to the boiler chassis.
4. Fit the new spark generator and reassemble in reverse order ensuring
the two earth leads are correctly
replaced.
5. Check operation of the boiler. Refer
to Frames 32-34.

Spark Generator
4

servicing

53 gas control valve replacement
1. Refer to Frame 44.

2. Unplug the electrical lead connection from the
gas control valve and disconnect the earth wire.
3. Undo the union nut on the outlet of the gas
control valve.
4. Undo the gas inlet pipe union at the inlet to the
gas control valve.
5. Loosen the back nut retaining the valve to the
bracket and withdraw the valve forwards.
6. Fit the new gas control valve ensuring the two
sealing washers are in place and reconnect gas
and electrical connections.
7. Check operation of the boiler. Refer to Frames
32-34.

5
2

Keston System - Installation and Servicing

SERVICING
54 condensate trap/Siphon replacement
1. Refer to Frame 44.
Note: Ensure condensate trap is fully drained before removal.

2. Pull off the rubber pipe at the sump drain.
3. Disconnect the condensate drain pipe.
4. Turn the siphon clockwise to disengage and lift to remove.
5. Reassemble in reverse order.
6. When reassembling ensure the trap is full of water.
7. Check operation of the boiler. Refer to Frames 32-34.

Servicing

Siphon

Keston System - Installation and Servicing

SERVICING
55 mAIN pcb rEPLACEMENT
Note that production boiler PCBs are factory pre-set to operate for boiler range and output, but when ordering Primary PCB as
a spare, an additional Boiler Chip Card (BCC) MUST also be purchased for your specific boiler range and output.

Note. Fit the earth strap provided with the
PCB to your wrist and secure to a suitable
earth on the boiler chassis.
1. Refer to Frame 44.
2. Note the control knob positions.
3. Remove the 2 screws retaining the control
box cover.

5. Unplug all lead connections to the PCB
including the ribbon cable (to facilitate
ribbon cable removal, ease side clips apart
and pull upwards), also where applicable,
push the small plastic clip with an electrical
screwdriver to facilitate plug removal.

servicing

4. Carefully lift the 4 retaining clips and
remove control box cover.

6. Spring out the two side retaining clips and
pull the PCB upwards to clear the 4 corner
retaining posts.
7. Take the new Primary PCB and attach the
appropriate Boiler Chip Card (BCC)

Note. Ensure the correct orientation of
BCC by placing “TOP” side up as shown.

8. Re-connect all plug connections.
9. Reassemble in reverse order.
10. Turn power back on to the boiler, after
a few moments the display will start
alternating between “F” and “0”. Turn the
reset knob fully clockwise and when the
display shows “ - ” turn the knob fully anticlockwise IMMEDIATELY.

Finally move the knob into the required
position.

11. Check operation of the boiler. Refer to
Frames 32-34.

5
Plastic
Clip

Ribbon Cable Connection

Keston System - Installation and Servicing

SERVICING
56 User control PCB replacement
Note. Fit the earth strap provided with the PCB
to your wrist and a suitable earth on the boiler
chassis.
1. Refer to Frame 44.
2. Remove the main PCB, refer to Frame 55.
3. Unclip the PCB and lift to clear the mounting
posts.
4. Fit the new PCB ensuring the 2 potentiometer
spindles line up with the control knobs which
must be in a vertical position.
5. Reassemble in reverse order.
6. Check operation of the boiler. Refer to Frames
32-34.
3

Servicing

4
Potentiometer spindle

PCB

Control Knobs (to be in vertical position)

3G9954

57 draining the boiler
CENTRAL HEATING CIRCUIT
1. Refer to Frame 44.
2. Close all the CH water isolating valves on the
boiler inlet.
3. To drain the primary heat exchanger circuit:
Open the drain valve and attach a length of hose
to the CH drain point.
4. After replacing any component on the boiler,
remove the hose, close the drain valve and
open all system isolating valves (re-pressurise
as appropriate) before proceeding to check
operation of the boiler.
5. Check operation of the boiler. Refer to Frames
32-34.

CH
Flow

Gas

CH
Circuit
Drain

CH
Retrun

3G9955

Keston System - Installation and Servicing

SERVICING
58 Pressure Gauge Renewal
1. Refer to Frame 44.

2. Drain the heating system. Refer to
Frame 57.
3. Unscrew the pressure gauge and
discard.
4. Fit new pressure gauge, using suitable
jointing compound.
5. Refill the boiler. Refer to Frame 22.
6. Check operation of the boiler. Refer to
Frames 32-34.

59 safety relief VALVE reNEWAL
1. Refer to Frame 44.
2. Drain the boiler. Refer to Frame 57.

3. Remove the condensate trap/siphon. Refer to
Frame 54.
4. Remove expansion vessel. Refer to Frame 65.

6. Disconnect the 22mm pipe connection at the rear
of the pump outlet.

7. Pull off the clip retaining the pipe to the heat
exchanger swing the pipe to clear the pump and
remove pipe.
5

8. Undo the safety valve union connection.
9. Withdraw the clip securing the safety valve.
10. Lift safety valve from boiler.
11. Fit the new safety valve and reassemble in
reverse order ensuring the new ‘o’ ring is fitted to
the top of the return pipe.

servicing

5. Disconnect the electrical connection from the
return thermistor.

12. Refill boiler. Refer to Frame 22. Check operation
of boiler. Refer to Frames 32-34.
6

60 Pump automatic air vent replacement
1. Refer to Frame 44.

Dust Cap

2. Drain the boiler. Refer to Frame 57.
3. Remove the expansion vessel. Refer to Frame 65.
4. Firstly, increase access area by disconnecting the 22mm pipe connection
at top of pump chamber and bottom of heat exchanger and remove pipe
Refer to Frame 59 (no’s 5,6 & 7).
5. The automatic air vent head is retained in the pump body with a bayonet
connection. The air vent head and float assembly is removed by turning
the head anti-clockwise (viewed from above) and pulling upwards.
6. Reassembly is the reverse of the above. Ensure the air vent head ‘o’ ring
seal is in place when refitting and the new ‘o’ ring is fitted to the return pipe
top connection.
7. Ensure the air vent cap is loose.
8. Refill the boiler. Refer to Frame 22. Check for leaks around the new air
vent joint.
9. Check the operation of the boiler. Refer to Frames 32-34.

Keston System - Installation and Servicing

SERVICING
61 Pump Head Replacement

1. Refer to Frame 44.
2. Drain the boiler. Refer to Frame 57.

3. Disconnect the electrical lead from the pump.
4. Remove the 4 Allen screws retaining the pump
head.
5. Remove the pump head.
6. Fit the new pump head.
7. Reassemble in reverse order.
8. Refill the boiler. Refer to Frame 22.

Servicing

9. Check operation of the boiler. Refer to Frames 35,
32-34.

62 CH Water Pressure sensor Replacement
1. Refer to Frame 44.
2. Drain the boiler. Refer to frame 57.
3. Remove condensate trap/siphon. Refer
to Frame 54.

4. Using a suitable tool pull out the
retaining clip.
5. Pull the pressure sensor upwards to
remove.
6. Unplug the electrical connection and
transfer to the new pressure sensor.
7. Push the new pressure sensor onto the
rear pump housing and fit retaining clip.
8. Reassemble in reverse order.

9. Refill the boiler. Refer to Frame 22.
10. Check Operation of the boiler. Refer to
Frames 32-34.

63 CONTROL / NO FLOW Thermistor Replacement
1. Refer to Frame 44.
2. Drain down the boiler. Refer to Frame 57.
3. Unplug the electrical lead.
4. Unscrew the thermistor (to facilitate removal a
13mm socket spanner should be used).
5. Fit the new thermistor using the sealing washer
provided.
6. Reassemble in the reverse order.

7. Refill the boiler. Refer to Frame 22.
8. Check the operation of the boiler. Refer to Frames
32-34.

Keston System - Installation and Servicing

SERVICING
64 heat engine reNEWAL
Refer also to Frame 5 - ‘Boiler Exploded View’
IMPORTANT
Before starting the removal procedure, protect the gas and electrical controls with a waterproof sheet or plastic bag.
1. Refer to Frame 44.

12. Undo the flow pipe union nut and remove pipe.

2. Drain the boiler. Refer to Frame 57.

13. Remove the condensate rubber pipe. Refer to Frame 54, no.
2.

3. Remove the fan / venturi assembly and place on one side.
Refer to Frame 45.

14. Remove the two heat exchanger fixing screws.
4. Remove the burner and place on one side. Refer to Frame 15. Remove the Heat exchanger.
47.
16. Reassemble in reverse order, ensuring the heat exchanger
5. Remove the ignition and detection electrodes. Refer to
LH retaining bracket is correctly positioned. Replace any
Frames 50 & 51.
new ‘o’ rings supplied with new heat exchanger and replacing
gaskets or seals if any sign of damage is evident. When
6. Remove the spark generator. Refer to Frame 52.
replacing the spring clips located on both the flow and return
7. Remove the gas valve. Refer to Frame 53.
pipe connections, ensure clip is oriented to correctly match
8. Remove the expansion vessel. Refer to Frame 65.
connecting pipe diameters.
9. Remove the control/no flow thermistor. Refer to Frame 63. 17. Ensure the trap/siphon is filled with water. Refer to Frame 55.
10. Remove the 2 M5 screws retaining the gas valve mounting
bracket and transfer bracket to the new heat exchanger.

19. Check operation of the boiler. Refer to Frames 32-34.

servicing

11. Undo the inlet pipe union nut and remove the retaining
spring clip and remove pipe.

18. Refill the boiler. Refer to Frame 22.

Keston System - Installation and Servicing

SERVICING
65 expansion vessel Recharging & replacement
RECHARGING
1. Remove the charge point cover.

Recharge
Point

2. Recharge the tank pressure to 0.75 bar.
3. Re-assemble in reverse order
4. Check operation of the boiler. Refer to
Frames 32-34.

REPLACEMENT
5. Refer to Frame 44.
6. Drain the boiler CH circuit. Refer to Frame 57.
7. Unscrew the union nut on the vessel water
connection pipe.

Servicing

8. Support the expansion vessel and unscrew
the 2 screws from the securing clamp, located
on the top of the boiler, and remove. (Note the
position of the bracket on the vessel)

9. Remove the expansion vessel.
10. Fit the new expansion vessel.
11. Reassemble in reverse order.
12. Refill the boiler. Refer to Frame 22.
13. Check operation of the boiler. Refer to
Frames 32-34.

66 Boiler sealing panel seal replacement
1. Refer to Frame 44.
2. Remove the old seal from the casing and
thoroughly clean the casing surfaces.
3. Fit the new seal, ensuring the bottom joint
provides an air tight seal.
5. Reassemble in reverse order.
6. Check operation of the boiler. Refer to
Frames 32-34.
Note. Ensure that the boiler front panel is
correctly sealed, compressing the seal
to make an airtight joint.

Keston System - Installation and Servicing

Fault finding
In order to assist fault finding the boiler has a 7 segment display. The key to the display codes is as follows:

ALTERNATING ‘L’ and ‘1’

GO TO FRAME 68 FLOW TEMPERATURE OVERHEAT LOCKOUT
or NO WATER FLOW LOCKOUT

ALTERNATING ‘L’ and ‘2’

GO TO FRAME 69 IGNITION LOCKOUT

ALTERNATING ‘L’ and ‘5’

5 RESETS WITHIN 15 MINS TURN POWER OFF AND ON

ALTERNATING ‘L’ and ‘6’

GO TO FRAME 70 FALSE FLAME LOCKOUT

ALTERNATING ‘F’ and ‘0’

BCC (BOILER CHIP CARD) NOT FITTED
SEE FRAME 55

ALTERNATING ‘F’ and ‘1’

GO TO FRAME 71 LOW WATER PRESSURE

ALTERNATING ‘F’ and ‘2’

GO TO FRAME 72 FLAME LOSS

ALTERNATING ‘F’ and ‘3’

GO TO FRAME 73 FAN FAULT

ALTERNATING ‘F’ and ‘4’

GO TO FRAME 74 CONTROL/NO FLOW THERMISTOR FAULT

ALTERNATING ‘F’ and ‘5’

GO TO FRAME 75 RETURN THERMISTOR FAULT

ALTERNATING ‘F’ and ‘6’

GO TO FRAME 76 OUTSIDE SENSOR FAULT

ALTERNATING ‘F’ and ‘7’

LOW MAINS VOLTAGE CONTACT ELECTRICITY PROVIDER

ALTERNATING ‘F’ and ‘9’

PCB FAULT **REPLACE PCB

ALTERNATING ‘c’ and ‘2’

GO TO FRAME 77 BCC FAULT (BOILER CHIP CARD)

ALTERNATING ‘c’ and ‘0’

RESET BOILER

No CH

GO TO FRAME 78

No hw

GO TO FRAME 80

CH & HW Operation Reversed

CHECK SYSTEM CONTROLS WIRING TO
BOILER SEE FRAME 28

No Display

GO TO FRAME 79

Note that production boiler PCBs are factory pre-set to operate for boiler range and output, but when ordering Primary PCB as a
spare, an additional Boiler Chip Card (BCC) MUST also be purchased for your specific boiler range and output.
**If PCB replaced as a spare ensure that the BCC (boiler chip card - small plastic part) is fitted to the PCB otherwise replace PCB.
RESET PROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.

Keston System - Installation and Servicing

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

67 fault finding chart MAIN MENU

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

Fault finding
68 aLTERNATING ‘L’ AND ‘1’ - FLOW TEMPERATURE OVERHEAT LOCKOUT OR nO
wATER fLOW LOCKOUT
Is the Boiler and CH System filled with water and all
isolation and radiator valves open?

Fill and vent the system and open all
isolation valves, then reset boiler

yes

Check that the Pump is rotating freely. Is
the Differential now below 20°C?

yes
If the PCB has been replaced check a BCC has been
fitted then reset the boiler.

Is the Flow/Return Differential across the Boiler in
excess of 30°C?

NO
Check the Control/No Water Flow and Return
Thermistors (Refer to Frame 48 & 63)

yes

Replace the Pump,
then reset boiler

OK, now
reset boiler

RESET PROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.

69 aLTERNATING ‘L’ AND ‘2’ - Ignition lockout
If the boiler is reset does the boiler ignite no
for a short time and then extinguish?
yes

Check gas supply and
rectify fault

yes

Check the detection electrode and
associated harness for: continuity,
visual condition and position (Refer to
Frame 51). Check if the condensate
pipe is blocked. Replace as necessary

Check ignition electrode and associated
harness for: continuity, visual condition
yes
and position. (Refer to Frame 50) Are
these functioning correctly?
yes

Is the Gas Pressure available at
the Boiler Inlet (>18 mbar)?

Check siphon and condensate drain
pipe work for blockage and rectify if
necessary. Boiler now working OK?

Is approx 215Vdc supply available
at the Gas Valve? (* See note)

yes
Unplug gas valve. Is resistance
between outside pins 4KΩ (±2)?

Check wiring connection
from gas valve to PCB for
continuity. If the wiring is
OK then replace the PCB
Replace Gas Valve

yes
Check spark generator and associated
harness for: continuity and visual
condition. (Refer to Frame 52) Are
these functioning correctly?

Replace Spark
Generator and harness
as necessary

Replace Ignition Electrode and
associated harness as necessary

No
Check flue for obstruction

yes

Clear obstruction

No
Check wiring to thermostat

yes

No
Check flue temperature always
remains below 90ºC

yes

Ensure wiring correctly
connected
Replace Thermostat

No
Check if burner is damaged
No
Replace heat exchanger

yes

Replace burner

* Note: due to the wave form of
the rectified voltage, the reading
will vary depending on the type
of meter used to measure the
value. In general terms a reading
greater than 150V indicates that
the correct voltage is supplied to
the gas valve.
RESET PROCEDURE - To reset
boiler, turn mode knob to reset
position and immediately turn
knob back to required setting.

Keston System - Installation and Servicing

Fault finding

Check routing and integrity of internal boiler
wiring is OK. Check condition of Flame Sense
Electrode and replace if deteriorated.

YES

Reset the boiler, does Boiler Work OK?
NO
Separate the flame detection electrode in-line
connector. Is there continuity between the terminals
pins connected to the electrode?

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

70 aLTERNATING ‘L’ AND ‘6’ - False Flame Lockout

yes

Replace Flame Detection Electrode

Check routing and integrity of internal boiler wiring.

RESET PROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.

71 aLTERNATING ‘F’ AND ‘1’ - Low Water Pressure
Is the Boiler and CH System filled with water and all
isolation and radiator valves open (check pressure
gauge is between 1 to 1.5 bar)?
YES

Fill and vent the system and open all isolation valves

Re-fit connections

yes

Are connections on water pressure sensor secure?

Replace water pressure sensor

72 aLTERNATING ‘F’ AND ‘2’ - Flame Loss
Does the boiler ignite for a short
time and then extinguish?

Is the Gas Pressure available at
the Boiler Inlet (18 mbar)?

yes

Check gas supply and
rectify fault

yes

Check the detection electrode and
associated harness for: continuity, visual
condition and position (Refer to Frame 51).
Check if condensate pipe is blocked. Check
if flue is blocked. Replace as necessary

Check siphon and condensate drain
pipe work for blockage and rectify if
necessary. Boiler now working OK?

YES

No
Check flue for obstruction
No
Check wiring to thermostat

Is 215Vdc supply available at the
Gas Valve while the flame is on?
(* See note)

yes
Check spark generator and associated
harness for: continuity and visual
condition. (Refer to Frame 52) Are
these functioning correctly?

Check wiring from gas
valve to PCB for continuity.
If the wiring is OK then
replace the PCB

Replace Spark Generator
and Harness as necessary.

yes
Check ignition electrode and associated
harness for: continuity, visual condition
and position. (Refer to Frame 56) Are
these functioning correctly?

Replace Ignition
Electrode and
associated harness as
necessary

No
Check flue temperature always
remains below 90ºC
No
Check if burner is damaged
No
Replace heat exchanger

YES
YES
YES
YES
YES

Replace Gas Valve
Clear obstruction
Ensure wiring correctly connected
Replace Thermostat
Replace Burner

Keston System - Installation and Servicing

Fault finding

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

73 aLTERNATING ‘F’ AND ‘3’ - Fan Fault

Does the wiring from the Fan to the PCB have secure connections at
both ends and has not deteriorated? Does the wiring have continuity?

NO
NO

yes
Is there 230Vac at the Blue and Brown connections
to the 3 way connection on the Fan?

YES

Rectify Wiring & connections
Replace PCB
Replace Fan

74 ALTERNATING ‘F’ AND ‘4’ - CONTROL / NO Flow Thermistor Fault

Remove the Control/No Flow Thermistor from the
Heat Exchanger and disconnect the wires.
Check the resistance using a suitable multimeter
connected across the thermistors terminal pins.
At 25 oC expect

9,700 - 10,300

At 60 oC expect

2,400 - 2,600

Ohms

At 85 C expect

1,000 - 1,100

Ohms

yes

Ohms

Fit a new Thermistor

Is there continuity between the PCB and Thermistor?
yes
Replace PCB

Is the Thermistor value correct?

no
Check and replace wiring as
necessary

75 aLTERNATING ‘F’ AND ‘5’ - Return Thermistor Fault

Remove the Return Thermistor from the CH Return
Pipe and disconnect the wires.
Check the resistance using a suitable multimeter
connected across the thermistors terminal pins.
At 25 C expect

9,700 - 10,300

At 60 oC expect

2,400 - 2,600

Ohms

At 85 C expect

1,000 - 1,100

Ohms

Is the Thermistor value correct?

Ohms

yes

Fit a new Thermistor

Is there continuity between the PCB and Thermistor?
yes
Replace PCB

no
Check and replace wiring as
necessary

Keston System - Installation and Servicing

Fault finding

Is the wiring securely connected at both the boiler and
Outside Sensor?
yes

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

76 aLTERNATING ‘F’ AND ‘6’ - Outside sensor fault
Securely connect the wiring at both the
boiler and Outside Sensor
Fit a new Outside Sensor

Disconnect the wires to the outside sensor.
Check the resistance using a suitable multimeter
connected across the Outside Sensors terminal pins.
At 0 oC

expect

31,000 - 35,000

At 15 oC expect

15,000 - 16,500

Ohms

At 30 C expect

7,700 - 8,500

Ohms

yes

Ohms

Is the wiring securely connected between the
incoming terminal block boiler connection of
the Outside Sensor and the PCB?
yes

Replace PCB

Is the Outside Sensor value correct?

no
Securely connect the wiring at
the Terminal Block and the PCB

77 aLTERNATING ‘c’ AND ‘2’ - BCC fault (Boiler CHIP card)
no

Is the correct BCC for the boiler securely inserted into the
slot at the front left of the PCB?
(identified by the label on the BCC)

Securely insert the correct BCC for the boiler
into the PCB and after switching power on and
‘c0’ being shown, reset boiler.
Note. Ensure the correct orientation of BCC by
placing “TOP” side up.

yes
Replace the BCC with a new BCC (that is correct for the
boiler). After switching power on and ‘c0’ being shown,
press reset. Is ‘c2’ still shown?

YES

Replace PCB

RESET PROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.

78 nO ch oPERATION

Move the mode knob to the ON position

Is the mode knob in the ON position?
yes
Are the Timer and the Room Thermostat or cylinder
thermostat switched on?
yes

Switch the Timer, Room Stat and Cylinder Stat On

Open the Radiator Valves

Are the Radiator Valves Open?
yes
Is there 230Vac at (A)?
yes
Check wiring from
terminal strip to
PCB.

NO
There is no Voltage from the
Timer/Room Stat. This is not
boiler fault. Ensure Voltage is
supplied to boiler by rectifying
external wiring.

L
N

Keston System - Installation and Servicing

Fault finding

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

79 No Display
no

Is there 230Vac to the boiler at L and N (see Frame 78)?

Supply power to the boiler

yes
Is the wiring from the terminal block to the Main PCB
connected securely?

Connect the wiring from the terminal block to the
Main PCB securely.

Connect the ribbon from the main PCB to the User
Interface PCB securely

yes
Is the ribbon cable from the main PCB to the User
Interface PCB connected securely?
yes
Is ribbon cable damaged?

yes

Replace the
User Interface
PCB

Replace ribbon cable

80 NO HW
Is the cylinder stat calling for heat?
yes

Is DHW timer on?
yes

Is boiler mode knob in the ON position?
yes
Is there 230V at (A) Refer to Frame 78?

Adjust cylinder stat

Switch timer on

Move the mode knob to the ON position

Check system controls and wiring

yes
Check wiring from terminal strip to PCB.

Keston System - Installation and Servicing

Short list of parts
When replacing any part on this appliance use only spare parts that you can be assured conform to the safety and performance
specification that we require. Do not use reconditioned or copy parts that have not been clearly authorised by Keston. Failure to do so
could affect safety or performance of this appliance.
Our Parts team are also available to help with your Keston Spare Parts enquiries on 01482 498665.
When calling, and to ensure we can provide you with the most accurate parts information, please ensure you have the following to
hand;
-

Boiler Model

Appliance GC Number

Boiler Serial Number

Keston System - Installation and Servicing

Benchmark Commissioning and
Servicing Section
It is a requirement that the boiler is installed and commissioned to the
manufacturers instructions and the data fields on the commissioning checklist
completed in full.
To instigate the boiler guarantee the boiler needs to be registered with the
manufacturer within one month of the installation.
To maintain the boiler guarantee it is essential that the boiler is serviced annually
by a Gas Safe registered engineer who has been trained on the boiler installed.
The service details should be recorded on the Benchmark Service Interval
Record and left with the householder.

GAS BOILER SYSTEM COMMISSIONING CHECKLIST
This Commissioning Checklist is to be completed in full by the competent person who commissioned the boiler as a means of demonstrating
compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.

CONTROLS
Programmable room thermostat
Optimum start control
Combination Boiler
Fitted
Fitted
Fitted
Automatic bypass to system

Fitted

Boiler interlock
ALL SYSTEMS
Yes

Yes
CENTRAL HEATING MODE
OR
mbar

mbar

Central heating return temperature
COMBINATION BOILERS ONLY
Yes
Yes
DOMESTIC HOT WATER MODE
OR
mbar OR

mbar

Cold water inlet temperature
Yes

Temperature

CONDENSING BOILERS ONLY
Yes
ALL INSTALLATIONS
AND

Ratio

AND

Ratio
Yes
Yes
Yes
Yes

* Allinstallations in England and Wales must be
to Local Authority Building Control (LABC) either directly or through a
Competent Persons Scheme. A Building Regulations Compliance
will then be issued to the customer.
www.centralheating.co.uk

SERVICE RECORD
It is recommended that your heating system is serviced regularly and that the appropriate Service Interval Record is completed.
Service Provider

SERVICE 01

SERVICE 02

AND
(Where Possible)

AND

²%
²%

(Where Possible)

Signature

SERVICE 03

SERVICE 04

AND
(Where Possible)

AND

²%
²%

(Where Possible)

Signature

SERVICE 05

SERVICE 06

AND
(Where Possible)

AND

(Where Possible)

Signature

SERVICE 07

SERVICE 08

AND
AND

(Where Possible)

Signature

SERVICE 09

SERVICE 10

AND

Signature

AND

²%
²%

Signature

(Where Possible)

AND

²%
²%

Signature

(Where Possible)

AND

²%
²%

AND

AND
(Where Possible)

AND

²%
²%

Signature

www.centralheating.co.uk

FLOWCHART FOR CO LEVEL AND COMBUSTION RATIO
CHECK ON COMMISSIONING A CONDENSING BOILER

Important Preliminary Information on Checks
The air gas ratio valve is factory-set and must not be adjusted DURING COMMISSIONING.
If the boiler requires conversion to operate with a different gas family (e.g. conversion from natural gas to LPG) separate guidance is provided with the conversion kit supplied and this must be followed.
PRIOR TO CO LEVEL AND COMBUSTION RATIO CHECK
The installation instructions must have been followed, gas type verified and gas supply pressure / gas rate checked as
required prior to commissioning.
As part of the installation process, ESPECIALLY WHERE A FLUE HAS BEEN FITTED BY PERSONS OTHER THAN
THE BOILER INSTALLER, visually check the integrity of the whole flue system to confirm that all components are
correctly assembled, fixed and supported. Check that maximum flue lengths have not been exceeded and all guidance
has been followed (e.g. Gas Safe Register Technical Bulletin (TB) 008 where chimney/flues are in voids).
The ECGA should be of the correct type, as specified by BS 7967.
Prior to its use, the ECGA should have been maintained and calibrated as specified by the manufacturer. The installer
must have the relevant competence for use of the analyser.
Check and zero the analyser IN FRESH AIR in accordance with the analyser manufacturer’s instructions.

KEY:
CO = carbon monoxide
CO2 = carbon dioxide
O2 = oxygen
Combustion Ratio = The CO reading measured in ppm divided by the CO2 reading first converted to ppm
ppm = parts per million
GS(I&U)R = Gas Safety (Installation and Use) Regulations

*Setting to Minimum Rate:
1. Turn the CH temperature control knob into the 10 O’clock position.
2. Create a heat demand by ensuring that the system controls are requesting heat and the boiler
Mode Knob is in the On Position.
3. Within an overall time of 3 seconds, turn the CH temperature control knob fully clockwise, back to
10 O’clock and then fully clockwise again.
4. “S” will be shown on the display and the boiler output will be reduced to minimum.
5. The boiler will remain at minimum rate for 5 minutes before reverting to normal operation.

Keston System - Installation and Servicing

Start

Set Boiler to Maximum Gas Rate
In accordance with boiler instructions,
set boiler to operate at maximum rate
(full load condition). Allow sufficient
time for combustion to stabilise.
Note. Do not insert analyser probe
during this period to avoid possible
flooding of sensor.

Carry Out Flue Integrity Check Using Analyser
Insert analyser probe into air inlet test point (where available) and allow
readings to stabilise.
Note. Where no air inlet test point is provided then a flue integrity check with
the analyser is not possible. The installer should verify that flue integrity has
been visually checked in accordance with the “Prior to CO level and
combustion ratio check” (see opposite page) before proceeding to the
“check CO level and combustion ratio at maximum rate” stage below.

Verify Flue Integrity
Analyser readings indicate that combustion products and inlet air
must be mixing. Further investigation of the flue is therefore required.
Check that flue components are assembled, fixed and supported as
per instructions. Check that flue and flue terminal are not obstructed.

Is
O2 more than or
equal to 20.6% OR CO2
less than or equal to
0.2%?

Yes
Is
O2 more than or
equal to 20.6% OR CO2
less than or equal to
0.2%?

Check CO level and Combustion Ratio
at Maximum Gas Rate

Yes

With boiler still set at maximum gas rate,
insert analyser probe into flue gas
sampling point. Allow readings to stabilise
before recording.

No
Turn off appliance and call Ideal Technical Helpline for advice
The appliance must not be commissioned until problems are identified
and resolved. If commissioning cannot be fully completed, the appliance
must be disconnected from the gas supply in accordance with GSIUR.

Yes

Check that no seals, e.g. Those on flue extensions, have
been displaced during installation. Rectify if necessary.

Is
CO level less
than 350ppm AND CO/CO2
ratio less than
0.0040?

Set Boiler to Minimum Gas Rate
(*see opposite page)
In accordance with boiler instructions, set boiler to
operate at minimum rate (to minimum load condition).
Allow sufficient time for combustion to stabilise.

Yes

Check CO and Combustion Ratio at Minimum Gas Rate
With boiler set at minimum rate, insert analyser probe into flue
gas sampling point. Allow readings to stabilise before recording.

No
Turn off Appliance and Call Ideal Technical Helpline
The appliance must not be commissioned until problems
are identified and resolved. If commissioning cannot be
fully completed, the appliance must be disconnected from
the gas supply in accordance with GS(I&U)R. NOTE:
Check and record CO level and combustion ratio at both
maximum AND minimum rate before contacting Ideal.

Is
CO level less
than 350ppm AND CO/CO2
ratio less than
0.0040?
Yes

Boiler is Operating Satisfactorily
No further actions required.
Ensure test points are capped, boiler case is correctly replaced and all
other commissioning procedures are completed. Complete Benchmark
Checklist, recording CO and combustion ratio readings as required.

Keston System - Installation and Servicing

Keston Heating, PO Box 103, National Avenue, Kingston Upon Hull, HU5 4JN
Tel. +44 (0) 1482 443005 Fax. +44 (0) 1482 467133.
www.keston.co.uk

February 2014

UIN 208893 A04

Keston pursues a policy of continuing improvement
in the design and performance of its products.
The right is therefore reserved to vary specification without notice.

System 30
User Instructions
FAN POWERED HIGH EFFICIENCY
MODULATING DOMESTIC CONDENSING
GAS BOILER
CE/PI No. 86-CL-08
System 30 - GC No. 41-930-39

These instructions must be left either with the
user or next to the site gas meter.

Keston Heating
PO Box 103, National Avenue, Kingston Upon Hull, HU5 4JN
Tel. +44 (0) 1482 443005 Fax. +44 (0) 1482 467133
email : info@keston.co.uk web : www.keston.co.uk
COMPLIANT WITH BUILDING REGULATION PART L1 & L2
SEDBUK A RATED

For any queries please ring the
KESTON consumer helpline : 01482 443005
NOTE. BOILER RESET PROCEDURE To reset boiler, turn mode control knob to reset position and immediately turn knob back to required setting.

Introduction

Minimum Clearances

Due to the high efficiency of the boiler, condensate is produced from
the flue gases and this is drained to a suitable disposal point through
a plastic waste pipe at the base of the boiler. A condensate ‘plume’
will also be visible at the flue terminal.

Bottom clearance
Bottom clearance after installation can be reduced to 5mm.

The Keston System is a wall mounted, room sealed, condensing
system boiler, featuring full sequence automatic spark ignition and fan
assisted combustion.

Safety

Current Gas Safety (Installation & Use)
Regulations or rules in force.

In your own interest, and that of safety, it is the law that this boiler
must be installed by a Gas Safe Registered Engineer, in accordance
with the above regulations.

Clearances of 165mm (6 1/2”) above, 100mm (4”) below,
2.5mm (1/8”) at the sides and 450mm (17 3/4”) at the front of
the boiler casing must be allowed for servicing.

This must be obtained with an easily removable panel, to
enable the consumer to view the system pressure gauge, and
to provide the 100mm clearance required for servicing.

To light the boiler. Refer to Frame 1

If a programmer is fitted refer to separate instructions for the
programmer before continuing.

1. Check that the electricity supply to boiler is
off.
In IE, the installation must be carried out by a Registered Gas Installer
(RGII) and installed in accordance with the current edition of I.S. 813
2. Set the mode control knob (B) to ‘Off’.
“Domestic Gas Installations”, the current Building Regulations and
3. Set the Central Heating temperature control (A) to ‘max’.
reference should be made to the current ETCI rules for electrical
4. Switch ON electricity to the boiler and check that all
installation.
external controls, e.g. programmer and room thermostat,
It is essential that the instructions in this booklet are strictly followed,
are ON.
for safe and economical operation of the boiler.
5. Set the mode control knob to ON.

Electricity Supply

The boiler will commence the ignition sequence supplying heat
to the central heating, if required.

Supply: 230 V ~ 50 Hz. The fusing should be 3A.

Note. In normal operation the boiler status display (C) will
show codes:

This appliance must be earthed.

Important Notes

 This appliance must not be operated without the casing correctly
fitted and forming an adequate seal.
 If the boiler is installed in a compartment then the compartment
must not be used for storage purposes.
 If it is known or suspected that a fault exists on the boiler then
it MUST NOT be used until the fault has been corrected by a
Gas Safe Registered Engineer or in IE a Registered Gas Installer
(RGII).

Standby - no demand for heat.
Heat being supplied.
Boiler frost protection - boiler will fire if temperature is
below 5 degrees C.
During normal operation the burner on indicator (D) will remain
illuminated when the burner is lit.

 Under NO circumstances should any of the sealed components on Note: If the boiler fails to light after five attempts the fault code
will be displayed.
this appliance be used incorrectly or tampered with.
 This appliance is not intended for use by persons (including
children) with reduced physical, sensory or mental capabilities, or
lack of experience and knowledge, unless they have been given
supervision or instructions concerning use of the appliance by a
person responsible for their safety.
 Children should be supervised to ensure that they do not play with
the appliance.

RESET PROCEDURE
To reset boiler, turn the mode control knob (B) to reset position
and immediately turn knob back to ON. The boiler will repeat
the ignition sequence. If the boiler still fails to light consult
a Gas Safe Registered Engineer or in IE a Registered Gas
Installer (RGII).

In cases of repeated or continuous shutdown a Gas Safe Registered
Engineer or in IE a Registered Gas Installer (RGII) should be called
to investigate and rectify the condition causing this and carry out an
operational test. Only the manufacturers original parts should be used
for replacement.

All Gas Safe Register installers carry a Gas Safe Register ID card, and have a registration number. Both should be recorded in the
Benchmark Commissioning Checklist. You can check your installer by calling Gas Safe Register direct on 0800 4085500.
Keston is a member of the Benchmark scheme and fully supports the aims of the programme.
Benchmark has been introduced to improve the standards of installation and commissioning of
central heating systems in the UK and to encourage the regular servicing of all central heating
systems to ensure safety and efficiency.
THE BENCHMARK SERVICE INTERVAL RECORD MUST BE COMPLETED AFTER EACH SERVICE

Keston System - User’s

Operation

Loss of system water pressure

The boiler controls the central heating radiator temperature to
a maximum of 80oC, adjustable via the CH temperature control
(A) or is automatically set by the weather compensation device
provided, the potentiometer adjusts the heating slope.

Re-pressurise via the filling loop to 1 bar (if unsure contact your
installer), turn off the tap on the filling loop and turn switch (B) to the
reset position and then back on again to reset the boiler.

The gauge (E) indicates the central heating system pressure. If the
Note. The pump will operate briefly as a self-check once every 24
pressure is seen to fall below the original installation pressure of 1-2
hours, regardless of system demand.
bar over a period of time then a water leak may be indicated. In this
event conduct the re-pressurising procedure as follows:
Control of water temperature

If unable to do so or if the pressure continues to drop after filling a
The Keston System is a high efficiency condensing boiler which is Gas Safe Registered Engineer or in IE a Registered Gas Installer
(RGII) should be consulted.
most efficient when operating in condensing mode.
Note. THE BOILER WILL not OPERATE if pressure has
The boiler will operate in this mode if the CH temperature control
reduced to LESS THAN 0.3 BAR UNDER THIS CONDITION.
(A) is set to the ‘e’ position (economy mode). This control should
be set to maximum for very cold periods

Condensate Drain

To shut down the boiler
Set the mode control knob to OFF.

To relight the boiler

Repeat the procedure detailed in ‘To light the boiler’.

Frost protection

If no system frost protection is provided and frost is likely during
a short absence from home, leave the heating controls (if fitted)
at a reduced temperature setting. For longer periods, the entire
system should be drained.
If the system includes a frost thermostat then, during cold
weather, the boiler should be turned OFF at the time switch (if
fitted) ONLY. The mains supply should be left switched ON, with
the boiler thermostat left in the normal running position.

Boiler Overheat Protection

The boiler controls will shut down the boiler in the event of
overheating. Should this occur, a fault code
will be displayed.
Refer to fault chart.

Flame Failure

Should this occur a fault code
chart.

The condensate drain (F) must not be modified or blocked.
Blockage of the condensate drain, caused by debris or freezing, can
cause automatic shutdown of the boiler.
If freezing is suspected and the pipe run is accessible an attempt
may be made to free the obstruction by pouring hot water over the
exposed pipe and clearing any blockage from the end of the pipe.
If this fails to remedy the problem the assistance of a Gas Safe
Registered Engineer or in IE a Registered Gas Installer (RGII)
should be sought.

Escape of gas

Should a gas leak or fault be suspected contact the National Gas
Emergency Service without delay. Telephone 0800 111 999
Do NOT search for gas leaks with a naked flame.

Cleaning

For normal cleaning simply dust with a dry cloth.
To remove stubborn marks and stains, wipe with a damp cloth and
finish off with a dry cloth.
DO NOT use abrasive cleaning materials.

will be displayed. Refer to fault

Maintenance

The appliance should be serviced at least once a year by a Gas
Safe Registered Engineer or in IE a Registered Gas Installer (RGII).

BOILER controls
Legend
A. CH Temperature Control

D. Burner ‘on’ Indicator

B. Mode Control

E. Pressure Gauge

C. Boiler Status

F. Condensate Drain

E
Keston System - User’s

G C

G. Economy Mode

F
3

Points for the BOILER User
Note. In line with our current warranty policy we would ask that you check through the following guide to identify any
problems external to the boiler prior to requesting a service engineers visit. Should the problem be found to be other
than with the appliance we reserve the right to levy a charge for the visit, or for any pre-arranged visit where access is
not gained by the engineer.

Troubleshooting
NO CENTRAL HEATING

NO HOT WATER

Check the mains switch (fused
spur) is turned on and ensure
mode control knob (B) is in the
ON position

Check the programmer is in
an “ON” position and the room
thermostat is turned up

Check the programmer is in an
“ON” position and the cylinder
thermostat is turned up

Does the boiler operate and
provide central heating?

Does the boiler operate and
provide hot water?

YES

Check the time settings on the
programmer are as you require
and adjust if necessary

See boiler “Operation Modes”
and “Fault Codes” section. If “0”
is displayed then contact a Gas
Safe Registered Engineer or in
IE a Registered Gas Installer
(RGII)

OPERATION MODES
DISPLAY CODE ON BOILER

DESCRIPTION
The boiler is in standby mode awaiting either a central heating call or hot water demand.

The boiler has a call for central heating / hot water but the appliance has reached the desired
temperature set on the boiler.

The boiler is operating for central heating / hot water.

The boiler is operating in frost mode.

continued . . . . . .

Keston System - User’s

fault codes
DISPLAY CODE ON BOILER

DESCRIPTION

ACTION

Boiler Chip Card (BCC)
Not Fitted

Please contact Keston (if under warranty) or alternatively a Gas Safe
Registered Engineer if outside of the warranty period. In IE contact a
Registered Gas Installer (RGII).

Outside Sensor Failure

Reset the appliance - if the boiler fails to operate then please contact
Keston (if under warranty) or alternatively a Gas Safe Registered
Engineer if outside of the warranty period. In IE contact a Registered
Gas Installer (RGII).

Low Mains Voltage

Contact a qualified electrician or your electricity provider.

PCB Fault

PCB Fault. Please contact Keston (if under warranty) or alternatively a
Gas Safe Registered Engineer if outside of the warranty period. In IE
contact a Registered Gas Installer (RGII).

5 Boiler Resets in 15 minutes

1. Turn power off and on at the fused spur.
2. If the boiler fails to operate please contact Keston (if under warranty)
or alternatively a Gas Safe Registered Engineer if outside of the
warranty period. In IE contact a Registered Gas Installer (RGII).

False Flame Lockout

BCC Activation Fault

BCC Fault

Low Water Pressure

Check system pressure is between 1 & 1.5bar on the pressure gauge.
If the boiler fails to operate then please contact Keston (if under
warranty) or alternatively a Gas Safe Registered Engineer if outside of
the warranty period. In IE contact a Registered Gas Installer (RGII).

Flow Temperature Overheat

Flame Loss

1. Check other gas appliances in the house are working to confirm a
supply is present in the property.
2. If other appliances do not work or there are no other appliances,
check the gas supply is on at the meter and/or pre payment meter
has credit. If the boiler fails to operate then please contact Keston
(if under warranty) or alternatively a Gas Safe Registered Engineer
if outside of the warranty period. In IE contact a Registered Gas
Installer (RGII).

Keston System - User’s

Fan Fault

Control / No Flow Thermistor

Return Thermistor

Keston Heating, PO Box 103, National Avenue, Kingston Upon Hull, HU5 4JN
Tel. +44 (0) 1482 443005 Fax. +44 (0) 1482 467133.
www.keston.co.uk
Keston pursues a policy of continuing improvement
in the design and performance of its products.
The right is therefore reserved to vary specification without notice.

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.6
Linearized                      : Yes
Create Date                     : 2014:02:12 11:03:00Z
Creator                         : Adobe InDesign CS6 (Windows)
Modify Date                     : 2014:02:12 11:53:00Z
XMP Toolkit                     : Adobe XMP Core 5.2-c001 63.139439, 2010/09/27-13:37:26
Metadata Date                   : 2014:02:12 11:53Z
Creator Tool                    : Adobe InDesign CS6 (Windows)
Instance ID                     : uuid:7ce1cc74-ba91-4ee2-af54-3df8a9fbe7a5
Original Document ID            : xmp.did:8B078078E8F6DF11814D92D18B0722F0
Document ID                     : xmp.id:DF531810D593E311B503B0D655ED5B3C
Rendition Class                 : proof:pdf
Derived From Instance ID        : xmp.iid:DE531810D593E311B503B0D655ED5B3C
Derived From Document ID        : xmp.did:161271F2208FE311A8F5C18BC7F83DEB
Derived From Original Document ID: xmp.did:8B078078E8F6DF11814D92D18B0722F0
Derived From Rendition Class    : default
History Action                  : converted
History Parameters              : from application/x-indesign to application/pdf
History Software Agent          : Adobe InDesign CS6 (Windows)
History Changed                 : /
History When                    : 2014:02:12 11:03:09Z
Format                          : application/pdf
Producer                        : Adobe PDF Library 10.0.1
Trapped                         : False
Page Count                      : 68

EXIF Metadata provided by EXIF.tools

Keston System 30Kw Installation Manual

Keston system 30 installation instructions Keston system 30 installation instructions

Navigation menu

Versions of this User Manual:

Views

Navigation