Ideal Industries Icos He12 Users Manual 203318 4.pmd

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2015-02-04

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installation and
servicing

icos

(V3 Flue System)
Your Ideal installation and servicing guide

For details of document amendments, refer to page 3

HE12, HE15, HE18, HE24
For users guide see reverse of book
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 Ideal Boilers.

April 2008

UIN 203318 A04

For the very latest copy of literature for specification purposes please visit our website
www.idealboilers.com where you will be able to download the relevant information in pdf format.

icos - Installation & Servicing

DOCUMENT AMENDMENTS
Relevant Installation changes implemented in this book from Mod Level ......................... A03 to A04 (Apr 08)
•

Page 15, Frame 11 - Unpacking
Change to boiler contents, wall mounting template now mounted on internal packaging.

•

Page 15, Frame 12 - Packaging Removal
Wall mounting template now mounted on internal packaging, frame changed to reflect this.

•

Page 17, Frame 16 - Wall Mounting Template
Wall mounting template now mounted on internal packaging, frame changed to reflect this.

Ideal Stelrad Group reserve the right to vary specification without notice

icos - Installation & Servicing

GENERAL
Table 1 - Boiler Data
Boiler Size

HE 12, HE 15, HE 18, HE 24
2H-G20-20 mbar Rc1/2 (1/2" BSP Female)

Gas supply type and connection
Injector size

Stereomatic 5.6mm dia. (HE 12 5.8mm dia).

Flow connection

22mm copper

Return connection

22mm copper

Flue terminal diameter

mm (in.)

100 (4)

Maximum static water head

m (ft.)

30.5 (100)

Minimum static water head

m (ft.)

0.45 (1.5)

Electrical supply

230 V ~ 50 Hz

Boiler power consumption

38W

Fuse rating

External: 3A Internal: T3.15A L250 V

Water content

litre (gal.)

1.7 (0.37)

Packaged weight

kg (lb.)

38 (84)

Maximum installation weight

kg (lb.)

31 (68)

Height mm (in.)

582 (23)

Width mm (in.)

390 (15)

Depth mm (in.)

278 (11)

Boiler size

Table 2 - Performance Data
Boiler Size
Boiler input 'Q' =

HE 12 Max HE 15 Max HE 18 Max HE 24 Max HE 12 Min HE 15-24 Min
Nett CV

kW
Btu/h

Gross CV

kW
Btu/h

Gas consumption
Boiler output 'P' =

70 C Mean water
temperature
40 oC Mean water
temperature

Seasonal efficiency (SEDBUK) *

12.2

15.1

18.7

24.4

9.8

9.1

41 600

51 500

63 800

83 300

33 400

31 000

13.5

16.8

20.7

27.1

10.9

10.1

46 000

57 200

70 800

92 500

37 200

34 400

l/s (cu.ft/h) 0.35 (44.2) 0.43 (54.7) 0.53 (68.0) 0.70 (89.7) 0.28 (35.6) 0.26 (33.3)
kW

12.0

14.6

18.2

23.4

9.3

8.8

40 900

50 000

62 300

80,000

31 800

30,000

12.7

15.5

19.2

25.1

10.5

9.6

Btu/h

43 300

53 000

65 700

85 700

35 900

32 800

Band A

[90.1]%

[90.4]%

[90.3]%

[90.2]%

Btu/h
kW

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.
Key to symbols

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)
3

b. For ft /h - divide the gross heat input (Btu/h) by the
gross C.V. of the gas (Btu/ft3)

GB = United Kingdom

IE = Ireland (Countries of destination)

PMS = Maximum operating pressure of water
C13 C33 C53 = A room sealed appliance designed for connection via
ducts to a horizontal or vertical terminal which admits
fresh air to the burner and discharges the products of
combustion to the outside through orifices which, in this
case, are concentric. The fan is up stream of the
combustion chamber.
I2H

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

CAUTION. To avoid the possibility of injury during the installation, servicing or cleaning
of this appliance, care should be taken when handling edges of sheet steel components.

icos - Installation & Servicing

GENERAL

icos

CONTENTS

Natural Gas only
Boiler size
HE12
HE15
HE18
HE24

G.C. Appliance No.
Benchmark No.

PI No.

41 397 95
41 397 83
41 397 84
41 397 85

87 BP 34
87 BP 34
87 BP 34
87 BP 34

Destination Countries:

GB, IE

Air Supply ....................................................................... 9
Benchmark Commissioning Checklist ..................... 54
Boiler Clearances ......................................................... 6
Boiler Exploded Diagram ............................................ 14
Electrical Connections ............................................... 27
Electrical Supply ........................................................... 9
Electrical Systems Diagrams .................................... 30
Extension Ducts - Fitting ............................................. 19
Fault Finding ................................................................. 45
Flow Wiring Diagram .................................................. 29
Flue Fitting .............................................................. 16-19
Flue Installation Requirements .................................... 8
Gas Safety Regulations ................................................ 7
Gas Supply ..................................................................... 8
Initial Lighting .............................................................. 31
Installation ............................................................. 14-32
Mandatory Requirements ............................................. 7
Safe Handling ................................................................ 8
Servicing ................................................................ 33-44
Short List of Parts ....................................................... 49
Terminal Guards ............................................................ 8
Thermostatic Radiator valves .................................... 9
Water and Systems ................................................ 9-13
Water Connections ................................................. 6, 27
Water Treatment ......................................................... 13
Wiring Diagrams ......................................................... 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.

BENCHMARK COMMISSIONING CHECKLIST DETAILS
Boiler

Page
Make and model ....................................................... 5
Appliance serial no. on data badge ...................... 14
SEDBUK No. % ......................................................... 4
Controls
Time and temperature control to heating ............. 30
Time and temperature control to hot water .......... 30
Heating zone valves .............................................. n/a
TRV's ......................................................................... 9
Auto bypass .............................................................. 9
Boiler interlock .......................................................... 9
For all boilers
Flushing to BS.7593 .............................................. 13
Inhibitor .................................................................. 13
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 ......................................................... n/a
Hot water mode
Heat input ............................................................... n/a
Max. operating burner pressure .............................. n/a
Max. operating water pressure ............................. n/a
Cold water inlet temp ............................................ n/a
Hot water outlet temp. ........................................... n/a
Water flow rate at max. setting .............................. n/a
For condensing boilers only
Condensate drain .................................................. 20
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

icos - Installation & Servicing

GENERAL
1

BOILER WATER CONNECTIONS

The boiler flow and return pipes are supplied fitted to the boiler
ready for top connection
Notes.
a. For the heating loads in excess of 60,000 Btu/h, 28mm (1") flow
and return pipes should be used to and from the boiler.
b. This appliance is NOT suitable for use with a direct hot water
cylinder.

BOILER CLEARANCES

all dimensions in mm (in.)

SIDE FLUE ONLY
Horizontal length of flue
from centre line of boiler
to outside wall

The following minimum clearances must be maintained for
operation and servicing.
Additional space will be required for installation, depending upon
site conditions.

0.5 m

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 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.

Top clearance
required (MIN.)
Dim. A
165 mm (6 1/2")

1.0 m

170 mm (6 11/16)

1.5 m

185 mm (7 1/4")

2.0 m

200 mm ( 7 7/8")

2.5 m

210 mm (8 1/4")

3.0 m

225 mm (8 7/8")

3.5 m

235 mm (9 1/4")

Installation from inside ONLY

4.0 m

250 mm (10 7/8")

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.

4.5 m

260 mm (10 1/4")

5.0 m

275 mm (10 13/16")

5.5 m

290 mm (11 3/8")

6.0 m

300 mm (11 13/16")

REAR FLUE ONLY
MIN. Top clearance required = 145 mm (5 3/4")

nm8729

Front clearance
The minimum front clearance when built in to a cupboard is
5mm (1/4") from the cupboard door but 450mm (17 3/4")
overall clearance is still required, with the cupboard door
open, to allow for servicing.
N.B. The boiler will not fit into a standard depth wall unit. In

order for it to do so the plastic fascia should be removed. See
Frame 41.

Bottom clearance
after installation can be reduced to 5mm in an adequately
ventilated enclosed cupboard. However, 100mm must be
available for servicing.

icos - Installation & Servicing

GENERAL
INTRODUCTION
The icos range of boilers are a fully automatically controlled,
wall mounted, low water content, balanced flue, fanned,
condensing gas boiler. It has full modulating central heating
outputs of :
HE12 9.3 kW (32,000 Btu/h) to 12.0 kW (41,000 Btu/h).
HE15 8.8 kW (30,000 Btu/h) to 14.6 kW (50,000 Btu/h).
HE18 8.8 kW (30,000 Btu/h) to 17.6 kW (60,000 Btu/h).
HE24 8.8 kW (30,000 Btu/h) to 23.4 kW (80,000 Btu/h).
Due to the high efficiency of the boiler a plume of water vapour
will form at the flue terminal during operation depending on
external conditions.
The boiler casing is of white painted mild steel with the user
controls capable of being mounted remotely from the boiler, if
the option is required.
The heat exchanger is of cast aluminium.
Note.
These boilers cannot be used on systems which include gravity
circulation.
The boilers are suitable for connection to fully pumped, open
vented or sealed water systems. Adequate arrangements for
completely draining the system by provision of drain cocks
MUST be provided in the installation pipework.

OPERATION
When there is a demand for heat, the heating system is
o
supplied at the selected temperature of between 30 C and
o
82 C.
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 PPE 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.

OPTIONAL EXTRA KITS
z
z
z
z
z

Flue Extension Ducts (1000mm long up to 6m)
Flue Finishing Kit
90o Elbow Kit (maximum 4 elbows per installation).
45o Elbow Kit (maximum 4 elbows per installation).
Roof Flue Kit (to a maximum of 7.5m)

icos - Installation & Servicing

z Powered Vertical Flue Kit 5 m primary and 17m secondary
is a typical maximum flue length. For further details refer to
Powered Vertical Fluing Instructions.
z High Level Flue Outlet Kits
z Flue Deflector Kit
z Weather Collar
z Twin Fluing Kits (to a maximum of 60m combined total of
flue and air ducts)
z Horizontal Flue 600mm long
z Remote User Control Kit
z Boiler Stand-off Kit
z Siphon Kit
z Condensate Pump Kit

SAFETY
Current Gas Safety (Installation and Use) Regulations or
rules in force.
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 CORGI
Registered Installer. It must be carried out in accordance with
the relevant requirements of the:
• Gas Safety (Installation and Use) Regulations
• The appropriate Building Regulations either The Building
Regulations, The Building Regulations (Scotland), Building
Regulations (northern Ireland).
• The Water Fittings Regulations or Water byelaws in
Scotland.
• 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 Competent
Person 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).

BS. 5449

Forced circulation hot water 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 60 kW.

BS. 6891

Low pressure installation pipes.

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 Ideal Stelrad Group in writing. If in doubt
please enquire.
Any direct connection of a control device not approved by Ideal
Stelrad Group may invalidate the certification and the normal
appliance warranty. It could also infringe the Gas Safety
Regulations and the above regulations.

GENERAL
SAFE HANDLING OF SUBSTANCES
Care should be taken when handling the boiler insulation
panels, which can cause irritation to the skin. No asbestos,
mercury or CFCs are included in any part of the boiler or its
manufacture.

LOCATION OF BOILER
The boiler must be installed on a flat and vertical wall, capable
of adequately supporting the weight of the boiler and any
ancillary equipment.
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 from the
back of the boiler.
The boiler must not be fitted outside.
Timber Framed Buildings
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.
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, in Scotland, 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 Ireland
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 can be installed in Zone 3, as detailed in BS.7671.

experienced ensure this is adequate for ALL other gas
appliances in the property.
IMPORTANT.
Installation pipes MUST be fitted in accordance with BS. 6891.
In IE refer to I.S.813:2002. Pipework from the meter to the boiler
MUST be of an adequate size, i.e. no longer than 20m and not
less than 15mm O.D.
The complete installation MUST be tested for gas soundness
and purged as described in the above code.

FLUE INSTALLATION
Pluming will occur at the terminal so terminal positions which
would cause a nuisance should be avoided.
The flue must be installed in accordance with the
recommendations of BS.5440-1:2000. In IE refer to I.S.813:2002.
The following notes are intended for general guidance.
1. The boiler MUST be installed so that the terminal is exposed
to external air.
2. It is important that the position of the terminal allows the free
passage of air across it at all times.
3. Minimum acceptable spacing from the terminal to
obstructions and ventilation openings are specified in Table 3.
Table 3 - Balanced Flue Terminal Position
Flue Terminal Positions

Min. Spacing*

1. Directly below, above or alongside an opening
window, air vent or other ventilation opening.

300mm (12")

2. Below guttering, drain pipes or soil pipes.
BS5440-1 2000

25mm ( 1")*
75mm (3")

3. Below eaves.
BS5440-1 2000

25mm (1")*
200mm (8")

4. Below balconies or a car port roof.
BS5440-1 2000

25mm (1")*
200mm (8")

Compartment Installations
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:
z BS. 6798. (No cupboard ventilation is required - see “Air
Supply” for details).
z The position selected for installation MUST allow adequate
space for servicing in front of the boiler.
z For the minimum clearances required for safety and
subsequent service see the wall mounting template and
Frame 2. In addition, sufficient space may be required to
allow lifting access to the wall mounting plate.

5. From vertical drain pipes or soil pipes.
BS5440-1 2000

25mm (1")*
150mm (6")

6. From an internal or external corner or to a
boundary along side the terminal.
BS5440-1 2000

25mm (1")*
300mm (12")

7. Above adjacent ground, roof or balcony level.

300mm (12")

GAS SUPPLY

* Only one reduction down to 25mm is allowable per installation
otherwise BS5440-1 2000 dimensions must be followed.

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.
The boiler MUST be installed on a gas supply with a governed
meter only.
A gas meter can only be connected by the local gas supplier or
by a CORGI registered engineer. In IE by a Competent Person.
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.
N.B. The principle of the 1:1 gas valve ensures that the icos
HE range is able to deliver it’s full output at inlet pressures
down to 14mb. However if dynamic pressures below 20mb are

8. From a surface or a boundary facing the terminal.

600mm (24")

9. From a terminal facing a terminal.

1,200mm (48")

10. From an opening in a car port
(e.g. door or window) into dwelling.

1,200mm (48")

11. Vertically from a terminal on the same wall.

1,500mm (60")

12. Horizontally from a terminal on the wall.

300mm (12")

Vertical Terminals
13. Above the roof pitch with roof slope of all angles.
Above flat roof.
14. From a single wall face.
From corner walls.

300mm (12")
300mm (12")
600mm (24")
1000mm (40")

4. Where the lowest part of the terminal is fitted less than 2m
(6'6") above a balcony, above ground or above a flat roof to
which people have access, then the terminal MUST be
protected by a purpose designed guard.
Ensure that the guard is fitted centrally.
Terminal guards are available from boiler suppliers. Ask for
TFC Flue Guard Model No. K6 (round plastic-coated). In
case of difficulty contact:
Grasslin (UK) Ltd.
Tower House, Vale Rise
Tonbridge. kent TN9 1TB

Tel. +44(0) 01732 359 888
Fax. +44(0) 01732 354 445
www.ffc.ukco.com

5. The flue assembly shall be so placed or shielded as to
prevent ignition or damage to any part of any building.

icos - Installation & Servicing

GENERAL
6. The air inlet/products outlet duct and the terminal of the
boiler MUST NOT be closer than 25mm (1") to combustible
material. Detailed recommendations on the protection of
combustible material are given in BS.5440-1:2000. In IE
refer to I.S.813:2002.

IMPORTANT.
It is absolutely ESSENTIAL to ensure, in practice, that products
of combustion discharging from the terminal cannot re-enter the
building or any other adjacent building through ventilators,
windows, doors, other sources of natural air infiltration, or forced
ventilation / air conditioning.
If this should occur the appliance MUST be turned OFF, labelled
as 'unsafe' until corrective action can be taken.

TERMINAL

Single feed, indirect cylinders are not recommended and MUST
NOT be used on sealed systems.
The appliances are NOT suitable for gravity central heating nor
are they suitable for the provision of gravity domestic hot water.
The hot water cylinder and ancillary pipework, not forming part
of the useful heating surface, should be lagged to prevent heat
loss and any possible freezing - particularly where pipes run
through roof spaces and ventilated underfloor spaces.
The boiler must be vented.
The hydraulic resistance of the boilers, at MAXIMUM OUTPUT,
o
o
with an 11 C (20 F) temperature differential, is shown in
Graph 1.

The terminal assembly can be adapted to accommodate
various wall thicknesses. Refer to Frame 14.

AIR SUPPLY
It is NOT necessary to have a purpose-provided air vent in the
room or internal space in which the boiler is installed. Neither is
it necessary to ventilate a cupboard or compartment in which the
boiler is installed, due to the low surface temperatures of the
boiler casing during operation; therefore the requirements of BS
6798, Clause 12, and BS 5440:2 may be disregarded. In IE the
requirements of I.S.813:2002 may be disregarded.

BOILER CONTROL INTERLOCKS
Ideal Stelrad Group recommend that 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 as stated in BS. 5449.
Central heating systems controls should be installed to ensure
the boiler is switched off when there is no demand for heating
or hot water.

WATER CIRCULATION SYSTEM
IMPORTANT.
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.
For the types of system and correct piping procedure see
Frames 1, and 3 to 8.
The central heating system should be in accordance with
BS.6798 and, in addition, for smallbore and microbore
systems, BS.5449.

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 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 without end switches,
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

WATER TREATMENT - see Frame 9
The hot water storage cylinder MUST be of the indirect type and
should preferably be manufactured of copper.

Graph 1 - Water flow rate and pressure loss

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 Ireland reference should be made
to the current ETCI rules for electrical installations.
The point of connection to the mains should be readily
accessible and adjacent to the boiler.

Pressure Drop Across Boiler
(metres water)

1.0
NOTE: THE FAN VOLTAGE IS 325V DC

CONDENSATE DRAIN - Refer to Frames 23 & 49

Ecl 1603

0.5

8.8

11.7

14.7
17.6
Boiler Output (kW)

icos - Installation & Servicing

20.5

23.4

A condensate drain is provided on the boiler. This drain must be
connected to a drainage point. All pipework and fittings in the
condensate drainage system MUST be made of plastic - no
other materials may be used.
IMPORTANT.
Any external runs must be insulated.
The drain outlet on the boiler is standard 21.5mm (3/4”)
overflow pipe.

GENERAL
3

OPEN VENT SYSTEM REQUIREMENTS

The system should be vented directly off the boiler flow pipe, as
close to the boiler as possible. The cold feed entry should be
inverted and MUST be positioned between the pump and the vent,
and not more than 150mm (6") away from the vent connection.
Note. Combined feed and vent pipes may also be fitted.
There should be a minimum height 450mm (18") of open vent
above the cistern water level. If this is not possible refer to
Frame 5. The vertical distance between the highest point of the
system and the feed/expansion cistern water level MUST not be
less than 450 mm (18"). The pump must be fitted on the flow side of
the boiler.
A suitable pump is a domestic circulator capable of providing a
o
o
maximum 11 C (20 F) temperature differential across the boiler with the
whole of the heating circuit open (e.g. Grundfos UPS 15/50, 15/60 or
equivalent). With the minimum flow circuit allowed by the controls the
o
o
differential must not exceed 25 C. (18 C for the HE15)
The vertical distance between the pump and feed/expansion cistern
MUST comply with the pump manufacturer's minimum requirements, to
avoid cavitation. Should these conditions not apply either lower the
pump position or raise the cistern above the minimum requirement
specified by Ideal Stelrad Group. The isolation valves should be fitted
as close to the pump as possible.

Return & flow
connections
load 30 - 60 = 22 mm
load 70 - 80 = 28 mm

SCHEMATIC PIPEWORK AND SYSTEM BALANCING

The boiler does not normally need a bypass but at least some
radiators on the heating circuit, of load 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 footnote re. thermostatic radiator valves).
Balancing
1. Set the programmer to ON for both CH
and HW. Turn the cylinder thermostat
down. 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
these lockshield valves to give boiler flow
and return temperatures not more than
o
20 C apart. These valves should now be
left as set.
2. Open all manual or thermostatic radiator
valves and adjust the lockshield valves
on remaining radiators to give around
o
11 C temperature drop at each radiator.
3. Turn up the cylinder thermostat and
adjust the cylinder balancing valve so
that the cylinder achieves a maximum
flow consistent with adequate flow to the
radiators. Check that with only the
domestic hot water loop in circuit a
o
differential temperature of 20 C across
the boiler is not exceeded.
4. Adjust room and cylinder thermostats
and programmer to NORMAL settings.

icos - Installation & Servicing

GENERAL
5

LOW HEAD AND LARGE SYSTEMS WITH EXTENSIVE PIPE RUNS - OPEN VENT

This arrangement is useful for large systems where
radiators at the extremities are difficult to vent. This can
lead to pumping over with conventional feed and vent
arrangements.
The following conditions MUST be observed:
1. The top of the automatic air vent must be below the
cold water level.
2. The static water level (cold) must be at least 200mm
above the top of the horizontal flow pipe, fitted as
shown. The vent connection MUST NOT be made
immediately off the top of the boiler as venting is
made less efficient.
3. The maximum practical length of 22mm cold feed pipe
should be used in order to reduce the effective volume
of hot system water expanding into the feed/expansion
cistern to a minimum.
Note. The pump manufacturers' minimum requirements must be complied with.

All dimensions in mm (in.).
NB. Imperial dimensions are approximate

SEALED SYSTEM REQUIREMENTS

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

Non-return
valve

b. When installing the
filling device, it must be
connected as shown to
fully comply with the
water regulations. This
may involve the fitting of
an additional WRAS
approval isolator valve
to the mains supply.

The installation
must comply with the
requirements of BS. 6798
and BS. 5449.

b. The installation should be designed to work with
flow temperatures of up to 82 oC.
c.

All components of the system, including the heat
exchanger of the indirect cylinder, must be
suitable for a working pressure of 3 bar (45lb/in2 )
and temperature of 110oC. Care should be taken
in making all connections so that the risk of
leakage is minimised.

2. Safety Valve
A spring loaded safety valve complying with the
relevant requirements of BS. 6759 must be fitted in
the flow pipe as close to the boiler as possible and
with no intervening valve or restriction. The valve
should have the following features:

icos - Installation & Servicing

Hosepipe
(disconnect
after filling)

Hose unions

Additional
stop valve

ecl6060

1. General

Automatic
air vent

Temporary hose
(disconnect
after filling)

Double check valve
assembly
(note direction of flow)

Hose connector

A non-adjustable preset lift pressure not exceeding
3bar (45lb/in2).

b. A manual testing device.
c.

Provision for connection of a discharge pipe.
The valve or discharge pipe should be positioned so
that the discharge of water or steam cannot create a
hazard to the occupants of the premises or cause
damage to electrical components and wiring.

3. Pressure Gauge
A pressure gauge covering at least the range 0-4 bar
(0-60 lb/in2) must be fitted to the system. The gauge
should be easily seen from the filling point and should
preferably be connected at the same point as the
expansion vessel.

GENERAL
7

SEALED SYSTEM REQUIREMENTS - continued

4. Expansion Vessel
a.

A diaphragm type expansion vessel must be
connected to a point close to the inlet side of the
pump, the connecting pipe being not less than 15 mm
(1/2" nominal) size and not incorporating valves of
any sort.

b. The vessel capacity must be adequate to accept the
expansion of the system water when heated to
110oC (230oF).
c.

The charge pressure must not be less than the
static water head above the vessel. The pressure
attained in the system when heated to 110o C (230o
F) should be at least 0.35 bar (5 Ib/in2) less than the
lift pressure of the safety valve.
For guidance on vessel sizing refer to the table in
Frame 8.
For further details refer to BS. 5449, BS. 7074:1 and
the British Gas Corporation publication 'Material and
Installation Specifications for Domestic Central
Heating and Hot Water'. For IE refer to the current
edition of I.S.813.

5. Cylinder
The cylinder must be either of the indirect coil type or a
direct cylinder fitted with an immersion calorifier which is
suitable for operating on a gauge pressure of 0.35 bar
(5 Ib/in2) in excess of the safety valve setting. Single feed
indirect cylinders are not suitable for sealed systems.
6. 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 150 mm (6") above the highest point of the
system, and be connected through a non-return valve
to the system, fitted at least 300 mm (12") below the
make-up vessel on the return side of the domestic
hot water cylinder or radiators.

or
b. Where access to a make-up vessel would be difficult
by pre-pressurisation of the system. Refer to 'Filling',
below.
7. Mains Connection
There must be no direct connection to the mains water
supply or to the water storage tank supplying domestic
water, even through a non-return valve, without the
approval of the local water authority.
8. Filling
The system may be filled by one of the following
methods:
a.

pressure. The cold feed pipe from the cistern should
include a non-return valve and a stop valve with an
automatic air vent connected between them, the stop
valve being located between the system and the
automatic air vent. The stop valve may remain open
during normal operation of the system if automatic
water make-up is required.
b. Through a self-contained unit comprising a cistern,
pressure booster pump (if required) and, if necessary,
an automatic pressure reducing valve and flow
restrictor. The cistern should be supplied through a
temporary connection from a service pipe or cold
water distributing pipe.
This unit may remain permanently connected to the
heating system to provide limited automatic water
make-up. Where the temporary connection is supplied
from a service pipe or distributing pipe which also
supplies other draw-off points at a lower level then a
double check valve shall be installed upstream of the
draw-off point.
c.

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 shall be used to facilitate
filling.
The following fittings shall form a permanent part of
the system and shall be fitted in the order stated:
A stop valve complying with the requirements of
BS. 1010, Part 2 (the hose from the draw-off tap shall
be connected to this fitting).
A test cock.
A double check valve of an approved type.
• Thoroughly flush out the whole of the system with
cold water, without the pump in position.
• With the pump fitted, fill and vent the system until the
pressure gauge registers 1.5 bar (21.5lb/in2).
Examine for leaks.
• Check the operation of the safety valve by manually
raising the water pressure until the valve lifts. This
should occur within ± 0.3 bar (± 4.3lb/in2.) of the
preset lift pressure.
• Release water from the system until the initial system
design pressure is reached.
• Light the boiler and heat the system to the maximum
working temperature. Examine for leaks.
• Turn off the boiler and drain the system while still hot.
• Refill and vent the system.
• Adjust the initial pressure to the required value.

Through a cistern, used for no other purposes, via a
ball valve permanently connected directly to a service
pipe and/or a cold water distributing pipe.
The static head available from the cistern should be
adequate to provide the desired initial system design

Sizing procedure for expansion vessels: The volume of the expansion vessel (litres) fitted to a sealed system shall not be
less than that given by the table on the following page, multiplied by a factor of 0.8 (for flow temperatures of less than 83o
C).

icos - Installation & Servicing

GENERAL
8

SEALED SYSTEM REQUIREMENTS - continued

Safety valve setting

3.0 bar

Vessel charge and initial
system pressure

0.5
bar

2.5 bar

1.0
bar

1.5
bar

Total water content of system
litres

0.5
bar

1.0
bar

2.0 bar
1.5
bar

0.5
bar

1.0
bar

Expansion vessel volume litres

2.1

2.7

3.9

2.3

3.3

5.9

2.8

5.0

4.2

5.4

7.8

4.7

6.7

11.8

5.6

10.0

6.3

8.2

11.7

7.0

10.0

17.7

8.4

15.0

100

8.3

10.9

15.6

9.4

13.4

23.7

11.3

20.0

125

10.4

13.6

19.5

11.7

16.7

29.6

14.1

25.0

150

12.5

16.3

23.4

14.1

20.1

35.5

16.9

30.0

175

14.6

19.1

27.3

16.4

23.4

41.4

19.7

35.0

200

16.7

21.8

31.2

18.8

26.8

47.4

22.6

40.0

225

18.7

24.5

35.1

21.1

30.1

53.3

25.4

45.0

250

20.8

27.2

39.0

23.5

33.5

59.2

28.2

50.0

275

22.9

30.0

42.9

25.8

36.8

65.1

31.0

55.0

300

25.0

32.7

46.8

28.2

40.2

71.1

33.9

60.0

Multiplying factors for
other system volumes

0.0833

0.109

0.156

0.094

0.134

0.237

0.113

0.20

WATER TREATMENT

The icos boiler range have an ALUMINIUM alloy heat exchanger
IMPORTANT. The application of any other treatment to this product may render the guarantee of Ideal

Stelrad Group invalid.
Ideal Stelrad Group recommend water treatment in accordance with the Benchmark Guidance Notes on Water
Treatment in Central Heating systems.

Ideal Stelrad Group recommend the use of FERNOX-COPAL or MB1,GE Betz Sentinel X100 OR Salamander Corrosion
Guard inhibitors and associated water treatment, which must be used in accordance with the manufacturers' instructions.
For further information contact:

Fernox Manufacturing Co. Ltd
Cookson Electronics
Forsyth Road
Sheerwater
Woking
Surrey
GU21 5RZ
Tel: +44 (0) 1799 521133

Sentinel Performance Solutions
The Heath Business & Technical Park
Runcorn
Cheshire
WA7 4QX
Tel: 0800 389 4670
www.sentinel-solutions.net

Salamander Engineering Ltd
Unit 24
Reddicap Trading Estate
Sutton Coldfield
West Midlands
B75 7BU
Tel: +44 (0) 121 3780952

Notes
1. It is most important that the correct concentration of the water
treatment product 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.

3. In hard water areas, treatment to prevent lime scale
may be necessary - however, the use of artificially
softened water is NOT permitted.
4. Under no circumstances should the boiler be fired
before the system has been thoroughly flushed.

BS. 7593:1992 details the steps necessary to clean a
domestic central heating system.

icos - Installation & Servicing

10 BOILER ASSEMBLY - Exploded view

40
94

nm8744

INSTALLATION

23. Control thermistor.
24. Overheat thermostat.
25. Ignition electrode.

LEGEND
15. Venturi assy.

26. Flame detection electrode.

16. Fan assy.

32. 'S' trap

17. Gas pipe assy.

33. Control assy.

19. Gas control valve assy.

40. Spark generator

20. Fan bracket assy.

44. Wall mounting plate.

13. Heat exchanger

21. Orifice plate.

53. Turret gasket kit.

14. Injector & housing

22. Flue thermistor.

94. Ignition lead

Front casing panel.

Sealing panel

10. Interpanel.

Sump cover plate.

11. Burner assy.

Bottom casing panel.

Flue sensing nipple.

12. Combustion chamber
Insulation.

Return pipe.

Flow pipe.

Flue manifold.

icos - Installation & Servicing

INSTALLATION

INSTALLATION
UNPACKING

The boiler is supplied fully assembled in one Pack A,
together with a telescopic flue assembly for lengths up to
595mm, rear or side flue outlet, in Pack B.
A
Unpack and check the contents.

D
Pack A Contents

The boiler

Wall mounting template
on cardboard

Wall mounting plate

1 year guarantee form

E
F

These Installation & Servicing/
User’s Instructions
Water Treatment Warning Label

Hardware pack

nm7890

Hardware Pack

A 50mm x No.14 wood screws - 3 off

D
C

B Wall plugs (TP2B ) - 3 off
C Push-in caps - 6 off (Refer to Frame 36 no. 15)
D Mains connector - 1 off

B Pack Contents

nm8465

A
C

A Telescopic flue terminal
B Flue turret
C Screws (2 off)

D Sealing Tape

nm8751

12 PACKAGING REMOVAL
1. Ensure the boiler is stood correctly, as marked on the
carton.
2. Cut and remove the strapping.
7

3. Fold back the top flaps to gain access to the wall
mounting plate, literature and wall mounting
template.
3

4. Remove the instructions and read thoroughly before
unpacking the product.
5. When ready for installation lift off the outer sleeve.

6. Remove the top protection packing/template and
save for further use.

7. Remove the two packaging ends.
8. Remove the hardware pack from under the pipes
and keep in a safe place.

7
nm9282

icos - Installation & Servicing

13 FRONT AND BOTTOM PANEL REMOVAL
3
1. To remove the front panel remove the 2 screws from the
bottom panel.
2. Lift the panel up and off the top pegs.
3. To remove the bottom panel remove the 2 screws.

4. Pull the RH side of the panel down. Slide it to the right
and withdraw.

14 DETERMINING THE FLUE LENGTH AND FLUE PACKS REQUIRED
IMPORTANT. The boiler MUST be installed in a vertical position.

Dimension X - Wall thickness.
Dimension L - Wall thickness plus boiler spacing.

FLUE KITS

Dimension S - Stand-off frame depth = 33mm.

Pack B - supplied as standard.
Finishing Kit - supplied as an optional extra.
Pack D - optional extension kit for side flue or rear flue outlet.
Refer to 'Flue Extension Ducts'
Note. MAXIMUM FLUE LENGTHS:

REAR FLUE

160 + S = 193mm

160 mm

HORIZONTAL FLUE - 6M
ROOF FLUE KIT - 7.5M
POWERED VERTICAL FLUE KIT - 5m primary and 17m secondary is a typical maximum
length. For alternative details refer to Powered Vertical
Instructions.
90O ELBOW KIT 60/100 (EQUIVALENT FLUE LENGTH RESISTANCE = 1M)
45O ELBOW KIT 60/100 (EQUIVALENT FLUE LENGTH RESISTANCE = 0.6M)
60/60 TWIN FLUE KIT - 18M TOTAL AIR PLUS FLUE DUCT - Ref Graph within Kit Instructions
80/80 TWIN FLUE KIT - 60M TOTAL AIR PLUS FLUE DUCT - Ref Graph within Kit Instructions
MINIMUM HORIZONTAL FLUE LENGTHS - TELESCOPIC TERMINAL = 370MM
(Centre Line of turret to outside of wall terminal) - ONE PIECE TERMINAL = 285MM

nm8943

INSTALLATION

Notes.
1. When extension ‘D’ packs are used the flue duct MUST be inclined at 1.5
degrees to the horizontal to allow condensate to drain back into the boiler
and out through the condensate drain.

Wall Thickness X

2. If the telescopic ‘B’ pack or horizontal flue terminal (600 long) only are
used, they may be mounted horizontally. The 1.5 degrees is taken care of
by the inclination of the flue within the air pipe
3. If the boiler is to be installed with downward piping routed behind the boiler
then the optional stand-off kit should be used. Care must be taken when
cutting the ducts and marking the wall to suit this condition.
Total Flue length dimension

Flue

(measuring from CL of turret to outside wall)

Rear flue
dim. X+160

Side flue
dim. L+195

Up to 595 mm

none

Up to 1545 mm

Pack D - 1 off

Up to 2495 mm

Pack D - 2 off

Up to 3445 mm

Pack D - 3 off

Up to 4395 mm

Pack D - 4 off

Up to 5345 mm

Pack D - 5 off

Up to 6000 mm

Pack D - 6 off

SIDE FLUE
Wall Thickness X
195mm 195mm

Extra packs
required

Side flue length L

icos - Installation & Servicing

INSTALLATION
15 FLUE ASSEMBLY - Exploded View
An optional flue duct extension kit is required for
wall thicknesses greater than :
Side 395mm
Rear 435mm

LEGEND
1. Duct assembly.

2. Flue turret.
3. Turret gasket.
4. M5 x 10 pozi screw.
5. Turret clamp.

Rear flue arrangement shown

nm8752

16 WALL MOUNTING TEMPLATE
The wall mounting template is located on the internal top
protective packaging.

Extended centre line
155

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.

V - See Diagram Below

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.
Note. If using stand-off kit distance increases to 188mm.

FLUE OUTLET

3. Mark onto the wall the following:
a The wall mounting plate screw positions (choose one
from each side with preference to top holes).
b. The position of the flue duct hole (see diagram below).

283

nm9

Note. Mark the centre of the hole as well as the
circumference.

nm8731

4. Remove the template from the wall.

icos - Installation & Servicing

INSTALLATION
17 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 hole (preferably with a 5" core boring
tool), ensuring that the hole is square to the wall.
Both wall faces immediately around the cut hole
should be flat.
2. Drill 3 holes with a 7.5mm / 8mm masonry drill and
insert the plastic plugs provided, for the wall
mounting plate and the jacking screw plate.
Note.
If using the stand-off kit then drill 4 holes (choosing
one from each group but not the jacking screw).
3. Locate 2 No.14 x 50mm screws in the piping frame
(one at each side, in any of the 3 holes provided at
each side) and screw home.
Note.
If using the stand-off kit then locate the stand-off
channel and screw home.

18 SETTING THE FLUE - REAR

Wall thicknesses of 210 to 435mm

Notes.
a. If using the extension ducts go to Frame 18.

Adhere sealing tape

Drill hole

b. If the stand-off frame is used it is essential to add 33mm
to dimension X.
c. For shorter flue requirements less than 210mm, use non
telescopic B Pack.

X + 75

FLUE OUTLET

1. Measure and note wall thickness X. Refer to Frame 12.
2. Add 75mm to dimension X and set telescopic flue length
as indicated in drawing.
3. Using a 3.5mm drill bit, drill two holes in outer air duct
taking care not to pierce plastic inner flue.

Measurement to be
taken from this point

4. Fix to length using self tappers provided.
nm8944

5. Seal outer air duct using the tape provided.

19 SETTING THE FLUE - SIDE

Wall thicknesses of 170 to 395mm

Notes.
a. If using the extension ducts go to Frame 18.

Adhere sealing tape

Drill hole

b. For shorter flue requirements use non telescopic B
Pack.
1. Measure and note wall thickness X. Refer to Frame 14.

L + 115

2. Measure distance from side of boiler to inside of wall
and add to wall thickness X=L. Refer to Frame 14.
3. Add 115mm to dimension L and set telescopic flue
length as indicated in drawing.
4. Using a 3.5mm drill bit, drill two holes in outer air duct
taking care not to pierce plastic inner flue.

Measurement to be
taken from this point

5. Fix to length using self tappers provided.
6. Seal outer air duct using the tape provided.

nm8945

icos - Installation & Servicing

INSTALLATION
20 FLUE EXTENSION DUCTS - For total flue lengths greater than 595mm
Pack D Flue extension duct kit contents.
Flue support cutting aid
(shown folded up)

Extension duct & clamp
1.0m (39") long

Wall plugs - 4 off

nm8732

Flue duct support

No. 10 x2" wood screw - 4 off

21 FLUE EXTENSION DUCTS - continued
Flue length
Use a maximum of 6m extended flue ONLY

Extension flue

General arrangement
1. A maximum of 6 extension ducts (one suitably
cut) plus the standard flue duct may be used
together.

Standard flue
Terminal grille

Boiler

Note. Side flue shown

nm8733

FLUE OUTLET

2. Flue extensions of greater length than 1m (39")
should be supported with the bracket provided,
suitably adjusted. Refer to Frame 20 & 26.

20 FITTING THE KIT
6. if the remainder Y is less than 300mm, shorten the
previous ‘D’ pack to 400mm and adjust the telescopic
terminal.

Because of the flexibility of the telescopic flue terminal it is not
always necessary to cut an extension pack.
1. Measure the total flue length from the centre of the boiler
outlet to the outside wall.

7. Measure and mark the length on the flue, to ensure a
square cut mark the flue all the way around and cut to
length.

2. Subtract 70mm from this dimension.
3. Subtract 950mm for each ‘D’ pack to be used.
4. If the remainder Y is 300mm 525mm this can be taken up
by the adjustment in the
telescopic flue.

L
70

950

Y
525
300

5. If the remainder Y is 525mm 950mm it will be necessary to
cut a ‘D’ pack to 400mm.

esp8940

icos - Installation & Servicing

23 CONDENSATE DRAIN
Refer also to the British Gas document: 'Guidance Notes for
the Installation of Domestic Gas Condensing Boilers' (1989).

The condensate drain provided on the boiler must be
connected to a drainage point, preferably within the
building.
Ensure that the condensate trap is full of water
before commissioning the boiler. Refer to Frame 27.
The routing of the drain must be made to allow a
minimum fall of 1 in 20 away from the boiler,
throughout its length.
The drainage pipework must be arranged so that
obstruction (e.g. through freezing) of external
drainage pipe does not give rise to spillage within
the dwelling.

Front View

IMPORTANT. If excessive external pipework cannot
be avoided an additional siphon kit and insulation
are recommended, in order to prevent possible
freezing.

Side View

All pipework and fittings in the condensate drain
system must be made of plastic. No other materials
may be used.

nm8734

INSTALLATION

155mm

The drain outlet on the boiler is standard 21.5mm
overflow pipe. This size must not be reduced in any
part of its length.
A plastic cap is fitted to the end of the condensate
drain adapter this must be removed before
connection is made.

Condensate
drain

24 CONDENSATE PIPE TERMINATION CONFIGURATIONS
Note. ALL EXTERNAL PIPE RUNS MUST BE INSULATED - MAXIMUM LENGTH 3M EXTERNAL

1. INTERNAL TO SINK WASTE
UPSTREAM OF SINK WASTE
TRAP

Sink constitutes
air break

BOILER

Open end of pipe
direct into gulley
below grating but
above water level

75mm trap

cla7771

Ground Level
DRAIN

2. INTERNAL TO SINK WASTE
DOWNSTREAM OF SINK
WASTE TRAP (PREFERRED
METHOD)

BOILER

Sink

Air Break

cla9252

Open end of pipe
direct into gulley
below grating but
above water level
75mm trap
Ground Level
DRAIN

continued . . . .

icos - Installation & Servicing

INSTALLATION

INSTALLATION
25 CONDENSATE PIPE TERMINATION CONFIGURATIONS . . . continued

3. INTERNAL CONNECTION TO SOIL AND VENT STACK
Termination into a down pipe can take place providing it can be confirmed that
the down pipe is part of a combined waste and rain water system.
* Make connection to SVP using a solvent welded saddle

BOILER

Air Break

cla9253

4. TERMINATION TO SOAK AWAY

External
wall

Termination
to Soak away

BOILER

cla7774

minimum
500mm

Ground Level

5. TERMINATION TO DRAIN / GULLEY

External
wall

Open end of pipe
direct into gulley
below grating but
above water level

BOILER

cla7775

Ground Level
DRAIN

icos - Installation & Servicing

INSTALLATION

INSTALLATION
26 MOUNTING THE BOILER
1

1. Lift the boiler onto the wall mounting plate, as
shown.
2. Check the boiler alignment using a spirit level
and adjust as necessary with the jacking screw.
3. Align the hole in the jacking plate with the predrilled hole in the wall and fix in position with the
No.10 x 2" screw provided.
4. Fit condensate union connection

27 CONNECTING THE FLUE TO THE BOILER
2
Note.

Before fitting the flue turret fill
the condensate trap within the
boiler by pouring a cupful of
water into flue outlet A.

Make sure the plastic cap is
removed from the end of the
condensate drain adapter.
Take care to ensure that the
water is only poured into the flue
outlet, and does not spill into the
boiler casing.

1. Locate the flue into the turret.

nm8755

2. Insert the flue assembly through the prepared hole in the
wall. Push through and pull back to seal against outside
wall face.
3. Locate the flue turret on the top of the boiler, ensuring that
the turret gasket is in place. Also ensure the turret is
located concentric with the flue aperture on the boiler top
panel. Check that the flue seal (at A) located in the top of
the flue manifold is secure and giving an effective seal.
4. Secure the flue turret on top of the boiler by inserting the
open ends of the turret clamp under the 2 studs and fixing
it in the middle with the single M5 x 10mm pozi-hex screw
provided.

5. Flues over 1 metre long.
Fix the flue support bracket to the wall, using the wall plug
and wood screw. For standard installations use the short
wood screw.
If the stand-off option is used, secure the support bracket
using the spacer bracket and long wood screw.
NB. The space bracket will utilise one fixing hole only whilst
used in conjunction with the stand-off option.

icos - Installation & Servicing

INSTALLATION
28 FITTING THE OPTIONAL ROOF FLUE KIT (Flat or Pitched)
Note.
A flat or pitched roof flashing plate (not supplied) is required before
proceeding with the installation of this kit.
This kit is suitable for both flat and pitched roof terminations, using a
concentric flue to run vertically from the top of the boiler and terminating
above roof level.
Connection to the top of the boiler is made using both a separately
supplied vertical connector and a 80/125 adaptor.
WEATHER PROOFING
Where the flue passes through the roof line an
adequate seal must be made. This is achieved
by using either:
-

Flat roof weather collar

or
-

Universal weather collar.

ACCESSORIES
Flue Duct Extension Kits are available for
flue lengths extending beyond 1m. These
packs contain 1m extension ducts and
may be cut to the desired length.
If the offset vertical option is used an elbow
Kit is required. For a full accessories list
refer to page 7, Optional Extras and Frame
31, Flue Arrangement.

29 ROOF FLUE KIT CONTENTS / OPTIONS
Flue Terminal
UIN 203132

Flue Seal Collar - Flat Roof
UIN 152259

Vertical connector
UIN 203135

90o elbow
UIN 203130

45o elbow
UIN 203131

Flue
duct
support

Flue Seal Collar - Tile Roof
UIN 152258

nm8735

Roof Flue Extension Duct
UIN 203129

icos - Installation & Servicing

FLUE OUTLET

nm8736

INSTALLATION
30 FLUE TERMINAL POSITION

The terminal should be positioned so that products of
combustion can safely disperse at all times.
Pluming may occur at the termination so, where
possible, terminal positions where this could cause
a nuisance should be avoided.

rf8392

Minimum dimensions are shown below

300mm

0m
30
in
m

min

rf8393-1

625mm
Fixed

300mm

Flat roof - with structure

690mm
Fixed
rf8394-1

FLUE OUTLET

min

Terminal Position

Minimum Dimension

Directly below an opening,
air brick, windows, etc.

300 mm

Below plastic / painted gutters

300 mm

Painted surface

300 mm

Below eaves or balcony

500 mm

icos - Installation & Servicing

INSTALLATION
31 FLUE ARRANGEMENT
Note.
The equivalent flue length resistance of the elbow kits are:
90o elbow kit = 1m

rf8737

FLUE OUTLET

rf8738

45o elbow kit = 0.6m

icos - Installation & Servicing

INSTALLATION
32 ASSEMBLING THE ROOF FLUE KIT
Determine the correct height that the flue should terminate
above the roof. If after calculating or measuring the overall flue
height from the top of the boiler, it is necessary to cut both
pipes of assembly A, then ensure they are cut equally leaving
the inner flue tube longer than the outer air tube as supplied.

1. Position the roof flashing plate (supplied separately) over the
hole cut in the roof and insert flue terminal from the roof end.
MAX LENGTH:
7.5m

max 41

min 16

Ensure the cut pipe ends are free from any burrs.

BOILER

nm8739

Flue Terminal
2. Push fit the vertical connector (supplied seperately) into the
boiler flue connection and retain with the turret clamp and
securing screw (supplied with the boiler). ENSURING THE
GASKETS IN THE BOILER FLUE OUTLET ARE CORRECTLY
FITTED.

Flat roof tile
weather collar

Pitched roof tile
weather collar

3. "Push" fit extension duct (if required (supplied separately)) into
vertical connector.

Extension
Duct

Turret
clamp
2
Vertical
connector

nm8741

nm8743

FLUE OUTLET

nm8740

4. If the last extension duct requires cutting, measure ‘X’, the distance
(outer ducts), between the duct and the terminal and add 100 mm to
this dimension. This gives the length of the last extension duct.
4

'X'

Note. Check the position of the inner flue duct relative to the outer duct
on the assembled extension duct(s) and ensure the terminal flue duct
is cut longer than the air duct to ensure engagement in the final flue
duct seal.
5. Finally ensure the roof flashing plate is correctly sealed to the roof.

icos - Installation & Servicing

INSTALLATION

INSTALLATION
33 GAS CONNECTION

IMPORTANT. The gas service cock is sealed with a non-metallic
fibre washer seal so must not be overheated when making
capillary connections.
Refer to Frame 2 for details of the position of the gas connection.
N.B. The principle of the 1:1 gas valve ensures that the icos
HE range is able to deliver it’s full output at inlet pressures
down to 14mb. However if dynamic pressures below 20mb
are experienced ensure this is adequate for ALL other gas
appliances in the property.

A boiler gas supply pipe length of 20m and not less than
15mm O.D. can be connected to the boiler via the gas
service cock union.
Ensure that the gas supply pipe does not foul the boiler
casing.
Refer to Frame 41 for details of the pressure test point
position.

34 BOILER WATER CONNECTIONS
The boiler flow and return pipes are supplied fitted to the
boiler and ready for top connection.
Note.
For heating loads in excess of 60 000 Btu/h use 28mm x
22mm connectors to connect the boiler flow and return
pipes to 28mm.

TOP CONNECTION
Connect the system pipework to the boiler flow and return
pipes.

Note.
The front panel is not fitted at this stage.

35 ELECTRICAL CONNECTIONS

WARNING. This appliance MUST be earthed.

Wiring should be 3 core PVC insulated cable NOT LESS
than 0.75 mm2 (24 x 0.2mm) and to BS. 6500, Table 16.

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

icos - Installation & Servicing

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,
or a plug and socket serving only the boiler and system
controls. The means of isolation must be accessible to the
user after installation.

36 INTERNAL WIRING
A pictorial wiring diagram is shown in Frame 37.
The mains lead connector is pre-fitted. This must be
removed to allow wiring.
1. Route the mains cable into the bottom LHS rear of the casing.
If using the stand-off kit then route through the grommet.
2. Wire a permanent live supply into the 5-way remote plug
terminals L3, N and .
IMPORTANT. A permanent live is ESSENTIAL in order for
the advanced diagnostic controls to function correctly.
3. Wire the switched live supply into L2 or connect L1 and L2
via external control switching, as shown in Frame 32. In
either case, remove the wire link fitted L1 to L2.
4. Secure the mains lead with the cable clamp.
5. Connect the mains lead connector. Ensure it is fully located.
Note.
Ensure that the lengths of the current carrying conductors are
shorter than the earth conductor so that if the cable slips in its
anchorage the current carrying conductors become taut
before the earth conductor.

Ecl 1542

Incoming mains wiring detail

L3
N
L2

Ecl2367

INSTALLATION

L1
Remove link when connecting external programmer.

Mains Connector

Socket

(supplied in hardware pack)

(fixed to boiler)

icos - Installation & Servicing

37 PICTORIAL WIRING DIAGRAM

r
y/g

Fan

Flue
thermistor

y/g
or

Overheat
thermostat

y y
Gas valve

Flow
control
thermistor

Chassis
earth y/g
b

y/g
bk

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

INSTALLATION

MAINS
SUPPLY
230V 50Hz
y/g
Spark generator
bk

Permanent
black link

y/g

y/g
br

User
control
and
display

b
Ferrite

b
or
Fused at
3.15ATL

Service
connection

ON /OFF
Switch

y
bk

Control PCB

r
nm 8076

r
pk
y

y/g
r

38 FUNCTIONAL FLOW WIRING DIAGRAM
Mains Switch

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

r
br

2
1

bk
y/g
External switch e.g.
room'stat, programmer
or
Overheat
or
thermostat

bk
y

r
DC
Fan

Control PCB

pk
b
Flame detection
electrode
y/g

L
E

DC Gas valve
Spark generator
y
Ignition electrode

Flue thermistor
CH return thermistor
(not fitted)
Control thermistor

icos - Installation & Servicing

User PCB
r

nm 7201

INSTALLATION

INSTALLATION
39 EXTERNAL ELECTRICAL CONTROLS
Wiring external to the boiler MUST be in
accordance with the current I.E.E. (BS.7671)
Wiring Regulations and any local regulations.
For IE reference should be made to the current
ETCI rules for electrical installations.
The fuse should be 3A.
Room Thermostat
If the thermostat has a neutral connection use it.
(It provides for more energy efficient operation by
reducing switching temperature differentials.)
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. This is usually done at the programmer, in
which case the programmer selector switches are
set to OFF and all other controls MUST be left in
the running position.
The frost thermostat should be sited in a cold place
but where it can sense heat from the system.
If the boiler is installed in a garage it may be
necessary to fit a pipe thermostat, preferably on
the return pipework.
Important. Ensure that the frost thermostat is
wired so that the system pump and/or external
diverter valve is energised, as appropriate.
Designation of the terminals will vary but the
programmer and thermostat manufacturers'
leaflets will give full details.

Diagram A shows an application to boilers fitted
with a room thermostat only.

Diagrams B and C show applications to boilers
fitted with alternative time controls.

Earths are not shown for clarity but MUST NEVER BE OMITTED.

40 COMMISSIONING AND TESTING
A. ELECTRICAL INSTALLATION

B. GAS INSTALLATION

1. Checks to ensure electrical safety should be carried out by
a competent person.

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

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.

WARNING.

Whilst effecting the required gas soundness test and purging air from the gas
installation, open all windows and doors, extinguish naked lights and DO NOT SMOKE.

icos - Installation & Servicing

INSTALLATION
INSTALLATION

41 INITIAL LIGHTING
1. Check that the system has been filled and that the boiler is not air locked.
Note.
It is important the burner is not operated before the system is fully
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
turned off.
2. Check that all drain cocks are closed and any valves in the flow
and return are open.
3. Check the electrical supply is off.
4. Ensure the boiler sealing panel is fitted.
5. Check the gas service cock is open.
6. Check that the boiler on/off switch (A) is OFF
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.
9. Set the boiler thermostat knob (B) to position 6 and switch the
boiler on/off switch (A) 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 3 attempts the fault codes L' 'F'
will be displayed. Press the reset button (E); the boiler will
then repeat its ignition sequence. When the burner is
established the WHITE burner ON neon (D) will be
permanently illuminated

N.B. The principle of the 1:1 gas valve ensures that the
icos HE range is able to deliver it’s full output at inlet
pressures down to 14mb. However if dynamic
pressures below 20mb are experienced ensure this is
adequate for ALL other gas appliances in the property.
IMPORTANT.
The gas input to the burner is regulated by the gas
valve according to the air flow produced by the fan.
It is NOT user-adjustable. Any interference to
sealed settings on the gas valve will adversely
affect operation and render our warranty void.

nm8780

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

LEGEND

H Gas service cock.

A On/Off switch.

B Thermostat knob.

K Overheat thermostat.

D 'Burner On' neon.

L Flue thermistor.

Casing pressure test point.

E Reset button.

M Flow thermistor.
F Injector pressure test point. Z Spark generator.
G Inlet pressure test point.

12. Switch OFF the boiler on/off switch.

THE DISPLAY

13. Remove the pressure gauge and tube. Tighten the
sealing screw in pressure test point. Ensure a gas
tight seal is made.

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 and the neon will show the status of the flame. If no
flame is detected the neon is blinking. When the flame is
detected the neon will be lit permanently.

14. Refit the boiler front panel and bottom panel.
15. THE FASCIA
a.

To remove the plastic fascia, prise off the
retaining star washers using a pair of pliers and
place to one side.

Fill the remaining fixing holes with the white push
in caps provided.

Below is a list with display function in normal operation.
Standby. No demand for heat present.
Boiler is active for central heating.
Boiler is in lockout for a specific error. The display will be
blinking, alternating with a number or letter to show which
error is detected.
Boiler is in lockout for a specific error. The display will be
blinking, alternating with a number or letter to show which
error is detected.
Boiler frost protection
Note: Boiler frost protection occurs at a temperature less
than 3 degrees. The boiler will fire.

icos - Installation & Servicing

INSTALLATION

INSTALLATION
42 GENERAL CHECKS
Make the following checks for correct operation:

Note. Fernox Superfloc, Sentinel X300 (new systems) or
X400 (existing systems) flushing solutions should be
used during the flushing procedure. Refer to Frame 9.
a. With the system HOT examine all water connections for
soundness.
b. With the system still HOT, turn off the gas, water and
electricity supplies to the boiler and drain down to
complete the flushing process.
c. Refill and vent the system, add inhibitor (see Frame 9),
clear all air locks and again check for water soundness.
Adhere the water treatment warning label, supplied in
the hardware pack, in a prominent position on the
system, to prevent the use of incorrect water treatment
additives.
d. Balance the system. Refer to Frame 4.

1. Central Heating
The correct operation of ANY programmer and all
other system controls should be proved. Operate
each control separately and check that the main
burner or circulating pump, as the case may be,
responds.
Ensure the external controls are calling for heat.
After ignition the display should read:

2. Gas Rate
Operate the boiler for 10 minutes. Check the boiler
gas rate (see Table 2), ensuring the boiler is at full
output whilst measurements are recorded.
3. Water Circulation System
Knob Setting

•

Flow Temperature
o
o
C
F

Min

Max

180

4. Check the condensate drain for leaks and check that it is
discharging correctly
5. Finally set the controls to the user’s requirements.

The temperatures quoted alongside are approximate, and
vary between installations.

43 HANDING OVER
After completing the installation and commissioning of the system the installer should hand over to the householder
by the following actions:
1. Hand the User's Instructions to the householder and
explain his or her responsibilities under current Gas
Safety (Installation and Use) Regulations or rules in force.
2. Explain and demonstrate the lighting and shutting 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 household requirements of both
heating and hot water consumption.
Advise the User of the precautions necessary to prevent
damage to the system and to 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 the boiler should be
turned off and a CORGI registered installer consulted. In
IE contact a competent person.
6. Explain and demonstrate the function of time and

temperature controls, radiator valves, etc., for the
economic use of the system.
7. If any programmer is fitted then draw attention to the
Programmer User's Instructions and hand them to the
householder.
8. After installation and commissioning please complete
the
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.
9. IMPORTANT
Stress the importance of regular servicing by a CORGI
registered installer and that a comprehensive service
should be carried out AT LEAST ONCE A YEAR. In IE
servicing work must be carried out by a competent
person.
10. As the installer you may wish to undertake the service
contract yourself or alternatively offer to the customer the
benefits of the Ideal Care Scheme, details of which are
outlined in the household pack supplied with this boiler.

icos - Installation & Servicing

SERVICING
44 SERVICING SCHEDULE
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.
Note.

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.

IMPORTANT.
8. After completing the servicing or exchange of components
always test for gas soundness.

It is the law that any service work must be carried out by a
CORGI registered installer. In IE service work must be
carried out by a competent person.

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

1. Light the boiler and carry out a pre-service check, noting
any operational faults.

Do NOT OPERATE the boiler if the sealing
panel is not fitted.

3. Clean the heat exchanger & ‘S’ trap.
4. Check the condition of the combustion chamber insulation.
Any cracked, damaged or displaced pieces should be
replaced.
5. Check the main injector for blockage or damage.
6. Wherever possible remove and clean the condensate ‘S’
trap (refer to Frame 44) and check the drain for blockage.

The servicing procedures are covered more fully in Frames
44-51 and MUST be carried out in sequence.

45 BOILER FRONT PANEL REMOVAL
1. Remove the 2 screws from the underside of the
appliance.
2. Pull the front panel forward at the bottom and lift
to disengage it from the top lugs.

10. If, for any reason, the condensate ‘S’ trap has been
removed ensure the trap is refilled with water before
reassembling.
11. Check the gas consumption.
12. Connect a suitable gas analyser to the sampling point on
the top of the boiler (refer to Frame 45) or into the flue
terminal if access is possible (optional test).
For correct boiler operation, the CO/CO2 content of the flue
gas should not be greater than 0.004 ratio.
13. Complete the service section in the Benchmark
Commissioning Checklist.

46 BOILER SEALING PANEL/
BOTTOM PANEL REMOVAL
1. To remove the sealing panel remove the 4 screws.
2. Remove the panel.
3. To remove the bottom panel remove the 2 screws.

nm7808

4. Pull the RH side of the panel down. Slide it to the right
and withdraw.

icos - Installation & Servicing

SERVICING

2. Clean the main burner.

7. Check that the flue terminal is unobstructed and that the
flue system is sealed correctly.

In order to carry out either servicing or replacement of
components the boiler front panel and sealing panel
must be removed. Refer to Frames 45 and 46.

SERVICING
47 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. Undo the screw on the fan mounting
bracket.

4
1

4. Lift off the fan and venturi assembly.
5. Inspect the injector for blockage or
damage.

SERVICING

Ecl 6073

48 BURNER REMOVAL AND CLEANING

1. Remove the 6 screws securing the
burner (the 3 screws at the rear are
extended to ease access).

2. Lift off the burner from the combustion
chamber.

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.

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

Ionisation
Probes

4. Inspect the sealing gasket around the
burner and combustion chamber
insulation for any signs of damage.
Replace as necessary.
Note.

740

Take care not to disturb the ionisation
probes at the front and rear of the
combustion chamber.

icos - Installation & Servicing

SERVICING
49 CLEANING THE CONDENSATE 'S' TRAP
1. Undo the plastic union nut on
the condensate ‘S’ trap outlet.
2. Remove the 2 screws.
3. Pull the trap down and forward
to remove.
4. Flush out any deposits with
clean water.

50 CLEANING THE HEAT EXCHANGER
1. Remove ignition and flame detection electrodes.
Refer to Frames 56 & 57.

2. Remove the 3 screws retaining the sump cover and
remove.

SERVICING

Ionisation
probes

3. Using a suitable tool as supplied in the standard
British Gas Flue brush kit, clean between the heat
exchanger fins from the top of the heat exchanger.

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

Sump cover

nm7401

4. Access to the base of the heat exchanger is now
possible. Brush clean any deposits from the base of
the heat exchanger and remove any loose deposits
from the sump.

6. Check the condition of the combustion chamber
insulation. Any cracked or damaged pieces must be
replaced.
Note. Take care not to disturb the ionisation probes at the
front and rear of the combustion chamber.
7. Check that the ignition and detection gaps are
correct. Refer to Frames 56 & 57.

Heat exchanger

51 REASSEMBLY
Reassemble the boiler in the following order.
1. Refit the condensate ‘S’ trap, ensuring that it is full of water.
2. Refit the sump cover plate.
3. Refit the electrodes (check dimensions Frames 56 & 57).

6. Reconnect the fan electrical leads.
7. Refit the boiler sealing panel.
IMPORTANT.
Ensure the boiler sealing panel is correctly fitted and
that a good seal is made.

4. Refit the burner.

8. Refit the boiler front and bottom panels.

5. Refit the fan / venturi assembly.

9. Turn on the gas supply at the gas service cock.
10. Reconnect the electrical supply.

icos - Installation & Servicing

SERVICING
52 REPLACEMENT OF COMPONENTS
GENERAL
When replacing ANY component:

1. Isolate the electricity supply.

IMPORTANT
When work is complete, the sealing panel must be
correctly fitted, ensuring that a good seal is made.

2. Turn off the gas supply.
3. Remove the boiler front panel. Refer to Frame 40.
After replacing ANY component check operation of the boiler
including gas soundness, gas rate and combustion test.

Note.
In order to assist fault finding, the control panel has an
LED diagnostic display. The key to boiler fault
conditions is shown in Frame 69.

SERVICING

THE BOILER MUST NOT BE OPERATED WITHOUT THE SEALING PANEL FITTED

53 CONTROL THERMISTOR REPLACEMENT
1. Refer to Frame 52.
2. Remove the boiler front and sealing panels. Refer
to Frames 45 & 46.
3. Pull the electrical leads off the control thermistor.
4. Pull the control thermistor and spring clip off the
flow pipe.
5. Replace thermistor and
reconnect leads, ensuring that
the spring clip is securely
holding the thermistor to the
flow pipe.
6. Reassemble the boiler in
reverse order.
7. Check the operation of the
boiler. Refer to Frame 52.

nm8753

icos - Installation & Servicing

SERVICING
54 FAN REPLACEMENT
Orifice plate
Gasket

1. Refer to Frame 52.
2. Remove the boiler front and sealing
panels. Refer to Frames 45 & 46.

3. Disconnect the electrical leads from
the fan.
4. Unscrew the gas pipe union
connection to the injector housing.

5. Unscrew and remove the screw
retaining the fan mounting bracket.
6. Remove the fan and venturi assembly.
7. Remove the 3 screws and remove the
venturi assembly, noting the
orientation of the venturi in relation to
the fan body.
8. Transfer the venturi assembly to the
new fan, replacing the gasket if
evidence of damage or deterioration
is visible.
9. Fit the new fan / venturi assembly.

Ecl 2336

SERVICING

10. Reassemble the boiler in reverse
order, taking care not to overtighten
the screw on the fan mounting
bracket.
11. Check the operation of the boiler.
Refer to Frame 52.

55 BURNER REPLACEMENT

1. Refer to Frame 52.
2. Remove the boiler front and sealing panels.
Refer to Frames 45 & 46.

3. Remove the fan assembly. Refer to Frame 49.

4. Remove the 6 screws securing the burner (the
3 screws at the rear are extended to ease
access).

5. Lift off the burner from the combustion
chamber.
6. Fit the new burner, replacing any damaged or
deteriorating sealing gasket.

Ionisation
Probes

7. Reassemble in reverse order.
8. Check the operation of the boiler. Refer to
Frame 52.
Note.

Take care not to disturb the ionisation
probes at the front and rear of the
combustion chamber.

icos - Installation & Servicing

740

SERVICING
56 IGNITION ELECTRODE REPLACEMENT
1. Refer to Frame 52.
2. Remove the boiler front and sealing panels. Refer
to Frames 45 & 46.
3. Unplug the ignition lead from the electrode.
4. Remove the earth lead from the ignition electrode.
5. Remove the remaining screw holding the ignition
electrode to the combustion chamber.
6. Remove the electrode.

ecl2780

7. Fit the new ignition electrode, using the
new gasket supplied. Check dimensions
as shown.

SERVICING

8. Reassemble in reverse order and check
that no damage to the combustion
chamber insulation has occurred during
the electrode replacement.
9. Check operation of the boiler. Refer to
Frame 52.

57 FLAME DETECTION ELECTRODE REPLACEMENT
1. Refer to Frame 52.
2. Remove the boiler front, bottom & sealing panels.
Refer to Frames 45 & 46.
3. Unplug the flame detection lead from the electrode.
4. Remove the 2 screws holding the flame detection
electrode to the combustion chamber.

5. Remove the flame detection electrode.
6. Fit the new flame detection electrode, using the
new gasket supplied. Check dimension as
shown.
7. Reassemble in reverse order and check that no
damage to the combustion chamber insulation
has occurred during the electrode replacement.
8. Check operation of the boiler. Refer to Frame 52.

icos - Installation & Servicing

SERVICING
58 SPARK GENERATOR REPLACEMENT
3

1. Refer to Frame 52.
2. Disconnect the leads from the spark generator and
bracket.

3. Remove the screw securing the spark generator bracket to
the flue casting.

4. Remove the 2 M4 screws securing the spark generator to
the bracket.

5. Fit the new spark generator and re-assemble in reverse
order.
6. Check operation of the boiler. Refer to Frame 52.
nm8745

59 BURNER INJECTOR REPLACEMENT
4

1. Refer to Frame 52.
2. Remove the boiler front and sealing panels. Refer to
Frames 45 & 46.

Copper washer

SERVICING

3. Remove the fan / venturi assembly. Refer to Frame 54.
4. Remove the 2 injector housing screws.
6. Withdraw the injector housing.
7. Fit the new injector housing, complete with injector.
8. Reassemble in reverse order, ensuring that the new
gas seal supplied is located correctly in the injector
housing.
9. Check operation of the boiler. Refer to Frame 52.

Rubber moulded seal
Ecl 2340

60 GAS CONTROL VALVE REPLACEMENT
1. Refer to Frame 52.
2. Remove the boiler front, bottom and sealing panels. Refer
to Frames 45 & 46.

10. Reassemble in reverse order.
11. Ensure the sensing tubing is correctly replaced and
not kinked or blocked in any way.

3. Unplug the electrical lead from the gas control valve and
disconnect the earth wire.

12. Check operation of the boiler. Refer to Frame 52.

4. Remove the sensing tube from the gas control valve.
5. Undo the union nut between the gas valve and the gas
inlet cock.

6. Undo the union nut on the outlet side of the gas
control valve.
7. Undo the gas valve bracket screw, slide the
gas valve forward and remove.
8. Transfer the mounting bracket and gas inlet
pipe to the new gas control valve.
9. Fit new gas control valve, ensuring that any
seals showing damage or deterioration are
replaced.

icos - Installation & Servicing

Ecl 2343

SERVICING
61 CONTROL BOX REPLACEMENT
1. Refer to Frame 52.
nm7804

2. Remove the front panel.
3. Remove the bottom panel.
4. Remove the 2 control box screws.
5. Carefully unplug all the electrical wiring from the control box.
6. With the control box lowered, pull the assembly forward to
remove from the housing.
7. Remove the user control from the assembly.
8. Transfer the mounting brackets to the new control box.
9. Reassemble in reverse order, ensuring that the control box is
located correctly in the housing before reconnecting the
electrical wiring.
10. Check operation of the boiler. Refer to Frame 52.

SERVICING

11.

Loosen the screw on the underside of the user control.

12.

Pull the display unit forward to remove.

13.

Push the new display unit into position.

14.

Reassemble in reverse order.

15.

Check the operation of the boiler. Refer to Frame 52.

Ecl 2438

N.B. To change the user control only.

Mounting brackets

11
Control box

Ecl 2419

62 MAINS SWITCH REPLACEMENT
1. Refer to Frame 52.
2. Remove the boiler front and bottom panel.
Refer to Frames 45 & 46.
3. Remove the 2 control box screws and lower
the control box.
4. Push out the mains switch from the rear, as
shown.
5. Refit the new switch, ensuring that the
electrical leads are replaced on the correct
terminals (refer to Frame 38) and the key
on the switch is correctly aligned with the
slot in the plastic moulding.
6. Reassemble in reverse order.
7. Check operation of the boiler. Refer to
Frame 52.

icos - Installation & Servicing

SERVICING
63 OVERHEAT THERMOSTAT REPLACEMENT
1. Refer to Frame 52.
2. Remove the boiler front and
sealing panels. Refer to Frames
45 & 46.
3. Pull off the electrical leads from
the thermostat body.
4. Pull the thermostat and clip from
the pipe.
5. Fit the new thermostat, ensuring
that the clip is securely holding
the thermostat to the flow pipe.
6. Reassemble in reverse order.

SERVICING

7. Check operation of the boiler.
Refer to Frame 52.

nm8746

64 FLUE THERMISTOR REPLACEMENT
1. Refer to Frame 52.
2. Remove the boiler front and sealing panels. Refer to Frames 45 & 46.
3. Pull off the silicon tube from the thermistor housing.
4. Remove the aluminium nipple securing the thermistor to the flue manifold.
5. Withdraw the thermistor.
6. Unplug the inline electrical connector.
7. Fit the new thermistor, using the gasket supplied.
8. Reassemble in reverse order.
9. Check operation of the boiler. Refer to Frame 52.

nm8747

icos - Installation & Servicing

SERVICING
65 COMBUSTION CHAMBER INSULATION REPLACEMENT
The insulation boards used in the combustion chamber of
this product are made of high temperature glass fibres with a
binder of organic and inorganic materials.
Ideal Stelrad Group recommend that, for your own comfort
and safety and to comply with good working practice, the
procedure described below is followed:
1. Refer to Frame 52.
2. Remove the boiler front and sealing panels. Refer to
Frames 45 & 46.

11. Sweep any dampened particles and place in the plastic
bag.

3. Remove the fan / venturi assembly. Refer to Frame 54.

12. Fit new insulation boards.

5. Remove the ignition electrode. Refer to Frame 56.
6. Remove the flame detection electrode. Refer to Frame 52.
7. Remove the front and rear ionisation probes.
Prior to removal of the board the following protective
equipment should be worn:
z Face mask supplied with the spare part.
z Gloves supplied with the spare part.

SERVICING

9. Remove the split pin and washer from the RHS of the
combustion chamber.
10. Remove the insulation boards. The replacement boards
are supplied in a plastic bag. This bag should be retained
and the discarded boards should now be placed into it.

4. Remove the burner. Refer to Frame 48.

8. Damp down the combustion chamber area containing the
insulation boards.

Note.
The boards are designed to be interlocking and should be
fitted as shown.
13. Fit the new split pin and washer in the RHS of the
chamber.
14. Remove the gloves and face mask and place them in the
plastic bag.
15. Wash your hands and any areas of skin which may have
come into contact with any of the particles from the
insulation board.
Note. Seal the plastic bag and dispose of it and its contents
into a commercial tip.
16. Reassemble in reverse order, remembering to re-fit the
ionisation probes first.
17. Check operation of the boiler. Refer to Frame 52.

Fit insulation in the following order:
1.

Rear.

Left Hand Side.

Front.

Right Hand Side.

LH Side

Front

Rear

7
RH Side

Combustion
chamber

5
nm8748

icos - Installation & Servicing

SERVICING
66 HEAT EXCHANGER REPLACEMENT
Refer also to Frame 10, 'Boiler exploded view'.

17. Remove the condensate 'S' trap. Refer to Frame 49.

1. Refer to Frame 52.

18. Unscrew the 2 M5 x 10 screws from the inter panel.

2. Remove front, bottom and sealing panels. Refer to
Frames 45 & 46.

19. Slide the heat exchanger and inter panel assembly
upwards to disengage and remove from the casing.

3. Remove the control box and place to one side. Refer to
Frame 61.

20. Transfer the interpanel to the new heat exchanger.

4. Attach a length of hose to the drain nipple on the bottom
of the heat exchanger and drain down the boiler.

21. Reassemble in reverse order, replacing gaskets or
seals if any sign of damage or deterioration is evident.

6. Remove the burner and place to one side. Refer to
Frame 48.

Note.
The heat exchanger is supplied with new combustion
chamber insulation boards. These should be fitted
(refer to Frame 65) before the burner and fan assembly
and before the ignition and detection electrodes are
replaced.

7. Remove the ignition and detection electrodes. Refer to
Frames 56 & 57.

25. Check the operation of the boiler. Refer to Frame 52.

5. Remove the fan assembly and place to one side. Refer
to Frame 54.

8. Remove the spark generator. Refer to Frame 58.
9. Release the flue from the turret.
10. Remove the turret from the boiler. Refer to Frame 15.
11. Release the silicon tubing from the sample point.

SERVICING

12. Release the electrical connections to the flue
thermistor.
13. Unscrew the M5 x 10 screw retaining the top manifold
flue casing.
14. Remove the top half of the flue manifold from the
appliance.

15. Undo the 4 M5 x 10 screws securing the bottom flue
manifold casting.
16. Pull the CH return pipe, CH flow pipe and the bottom
flue manifold together up and out of the heat
exchanger.

15
nm8749

icos - Installation & Servicing

SERVICING
67 BOILER SEALING PANEL SEAL REPLACEMENT
1. Refer Frame 52.
2. Remove the front panel. Refer to Frame 45.
3. Remove the boiler sealing panel. Refer to
Frame 46.

4. Remove the old seal from the casing and
thoroughly clean the casing surfaces.
5. Fit the new adhesive seals - note that they
are supplied to the correct length for the
relevant sides.
6. Reassemble in reverse order.
Note.
Ensure that the boiler sealing panel is
correctly seated, compressing the seal to
make an airtight joint.
7. Check operation of boiler. Refer to
Frame 52.

SERVICING

Seals

68 CONDENSATE 'S' TRAP REPLACEMENT
1. Refer to Frame 52.

5. Remove the 2 screws.

2. Remove the boiler front panel. Refer to Frame 45.

6. Pull the trap down and forward to remove.

3. Remove the boiler bottom panel. Refer to Frame 46.

7. Reassemble in reverse order, ensuring that the new
trap is full of water.

4. Undo the plastic union nut on the condensate 'S' trap
outlet.

8. Check operation of the boiler. Refer to Frame 52.

4
2
nm 2902

icos - Installation & Servicing

FAULT FINDING
FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

69 FAULT FINDING CHART MAIN MENU
In order to assist fault finding the boiler has an LED diagnostic display. The key to the display codes is as follows:

ALTERNATING 'L' 'F'

GO TO FRAME 70

ALTERNATING 'L' 'E'

GO TO FRAME 71

ALTERNATING 'L' 'A'

GO TO FRAME 72

ALTERNATING 'L' '8'

GO TO FRAME 73

ALTERNATING 'H' '1'

GO TO FRAME 74

ALTERNATING 'H' 'F'

GO TO FRAME 75

ALTERNATING 'H' '4'

GO TO FRAME 76

ALTERNATING 'H' 'n'

GO TO FRAME 77

ALTERNATING 'H' 'E'

GO TO FRAME 71

ALTERNATING 'H9'

GO TO FRAME 76

ALTERNATING 'L9'

GO TO FRAME 76

icos - Installation & Servicing

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

FAULT FINDING
70 L.....F.......

(FLAME ERROR)

If the boiler reset button is
pressed does the boiler ignite for
a short time then extinguish?

Is gas pressure available at
the boiler inlet ?

YES

Check gas supply
and rectify fault

YES

Check the detection electrode and
associated harness for:

Is 200V DC supply available
at the gas valve ?

continuity, visual condition, position
(Refer to Frame 57).

Check gas valve
wiring for
continuity

Replace as necessary.
YES
Check spark generator and associated
harness for continuity and visual condition.
Refer to Frame 58. Are these functioning
correctly?

Replace PCB
NO

Replace
spark generator

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

Check syphon
and condensate
drain pipework
for blockage

YES

NO
Replace ignition electrode and associated
harness as necessary

Replace gas valve

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 (some may measure the possible peak voltage of 339V). In general terms, a reading greater
than 150V indicates that the correct voltage is supplied to the gas valve. As an alternative to a multimeter a
mains checking device may be used. E.g. an electrical screwdriver or a mains tester.

71 L.....E......

H.....E......

(BOARD ERROR)

Check for an excess voltage between neutral NO
and earth. Is the value below 50V?
YES

LE ONLY: Check continuity of OH thermostat.
Is this correct?
YES
HE ONLY: Check earth wire is connected to
detection lead. Is this correct?
YES
Check all earths for continuity

YES

Check earth connection to the boiler. If value is still in
excess of 50V consult a Qualified Electrician to check the
household electrical supply and circuitry
Correct wiring or replace thermostat
Correct wiring or replace detection lead

NO
Correct connections
NO

Press and hold reset button for 2
seconds. Does boiler operate
correctly?

NO
Turn boiler off and wait for 5
seconds.Turn boiler on.
Does boiler operate correctly?

Internal fault within the PCB

YES

NO
Replace PCB

icos - Installation & Servicing

FAULT FINDING
(OVERHEAT ERROR)
NO

Can the overheat condition be reset by pressing
the boiler reset button when the system is cold ?

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

72 L.......A........

Replace overheat thermostat

YES
NO

Is the boiler and CH system filled with
water and all isolation valves open ?

Fill and vent the system and open all
isolation valves

YES
NO

Does the pump setting give a differential
o
across the boiler in excess of 25 C ?

Set CH control knob to maximum.
If the overheat trips again measure the flow temp:

YES

Over 90 C Check control thermistor
(Refer to Frame 71) .

Increase the pump setting.

Under 90 C Replace overheat 'stat

Is differential now below 25 C ?
Note.

YES

NO
Replace the system pump

With V9 Primary Control PCB, overheat LA/HA or H9/L9 when
reset will display 3 horizontal lines and will not attempt to refire
until the temperature in the heat exchanger drops below 50oC.

73 L....8..... (FAN ERROR)
Is nominal 330 V DC present across
red and blue at the fan connector as
reset button is pressed?

YES

Is 14V DC present
across yellow and pink
at the fan connector?

Replace fan

YES
Check wiring harness for continuity. Is there continuity?

74 H.....1.....

YES

Replace PCB
Replace harness

(FLOW THERMISTOR ERROR)

Remove the boiler flow thermistor from the CH flow
pipe and disconnect thermistor wires.

Check resistance, using a suitable multimeter
connected across the thermistors terminal pins
o

expect

9,700 - 10,300

Ohms

expect

2,400 -

2,600

Ohms

expect

1,000 -

1,100

Ohms

At 25 C
At 60 C
At 85 C

Are the thermistor values correct ?
YES

Is there continuity between the
PCB and the thermistor ?

icos - Installation & Servicing

YES
NO

Replace the thermistor

Replace PCB
Check and replace wiring as necessary

FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING

FAULT FINDING
75 H......F........

(FLAME DETECTION - SHORT CIRCUIT ERROR)

Remove flame detection electrode terminal from PCB.
NO

Replace PCB.

Is there continuity between the 2 terminal pins ?
YES

Replace flame detection electrode

76 H.....4...... (FLUE THERMISTOR ERROR)

H9/L9 (HEAT EXCHANGER OVERHEAT)
Is the system filled and vented and all
isolation valves open ?

Can the fault condition be reset by switching
off the mains supply to the boiler ?

Is the pump operating correctly? Ensure
flow through system.

YES

Check wiring for continuity from the
PCB to the flue thermistor

Fill and vent the
system and open all
isolating valves

Check resistance, using a suitable multimeter
connected across the flue thermistor terminal
pins.

Check resistance, using a suitable multimeter
connected across the thermistor terminal pins.
o

9,700 - 10,300

Ohms

2,400 -

2,600

Ohms

1,000 -

1,100

Ohms

At 25 C expect
At 60 C expect
o

At 85 C expect

9,700 - 10,300 Ohms

2,400 -

2,600 Ohms

1,000 -

1,100 Ohms

At 25 C expect
At 60 C expect
At 85 C expect

Are thermistor values correct ?
YES

Replace PCB

Are thermistor values correct ?
YES

Replace thermistor

Inspect heat
exchanger for
blockage or damage
in the flueways.
Clean or replace as
necessary

Replace thermistor

Note.
With V9 Primary Control PCB, overheat LA/HA or H9/L9 when
reset will display 3 horizontal lines and will not attempt to refire
until the temperature in the heat exchanger drops below 50oC.

77 H......n........

(PHASE REVERSAL ERROR)
Check wiring to the boiler for
reversed live and neutral

icos - Installation & Servicing

SHORT LIST OF PARTS
The following are parts commonly required due to damage or
expendability. Their failure or absence is likely to affect safety or
performance of this appliance.

When ordering spares please quote:
1. Boiler Model
2. Appliance G.C. Number

The list is extracted from the British Gas List of Parts, which
contains all available spare parts.

3. Description
4. Quantity

The full list is held by British Gas Services, Ideal Stelrad Group
distributors and merchants.

5. Product Number

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 Ideal Boilers Limited.
Key No.

GC Part No.

Description

Qty.

Product No.

Front casing panel

173 508

E67-482

Bottom casing panel

170 900

E67-489

Burner

170 905

Combustion chamber insulation

173 520

12
14

E67-492

Injector and housing

HE15, HE18, HE24

170 908

H18-545

Injector and housing

HE12

173 779

E85-097

Fan assembly

172 625

E67-497

Gas control valve

170 913

E67-500

Flue thermistor

170 916

E67-501

Control thermistor

170 917

E67-502

Overheat thermostat

170 918

Ignition electrode kit

173 528

Flame detection electrode and gasket

173 529

E67-511

Condensate ‘S’ trap

170 926

E65-515

Controls hinge bracket kit

170 928

User controls

173 532

PCB primary controls kit (V9)

174 486

Fuse PCB (3.15A L 250V)

170 931

Main switch c/w harness

173 537

E67-519

39
45

E65-527

Gasket kit

170 938

E68-376

Seal kit - sealing panel

171 014

E68-380

Turret gasket

171 022

Spark generator

173 538

Ignition lead

173 510

Detection lead

173 511

icos - Installation & Servicing

SHORT LIST OF PARTS
78 SHORT LIST

nm8077

79 BOILER CASING ASSEMBLY
1. Front casing panel with screws.
2. Sealing panel with screws.
4. Bottom casing panel with screws.

icos - Installation & Servicing

LIST OF PARTS
80 CONTROLS ASSEMBLY
33.

Controls assy with screws.

34.

Controls hinge bracket.

35.

User controls (without item 38).

36.

PCB (primary controls).

38.

User control housing

39.

Mains switch.

54.

Jumper link.

81 BURNER ASSEMBLY
11. Burner assembly with screws
and gasket.

Ecl 1598

icos - Installation & Servicing

NOTES

icos - Installation & Servicing

INSTALLER NOTIFICATION GUIDELINES
IT IS A REQUIREMENT OF CORGI MEMBERSHIP TO REGISTER EVERY GAS APPLIANCE
In addition a change to Building Regulations (England and Wales) requires the installer to notify
when installing a heating appliance, as from 1st April 2005.

Install and commission
this appliance to
manufacturers' instructions

Complete the
Benchmark Checklist

Competent Person's
SELF CERTIFICATION SCHEME

If you notify via CORGI Scheme,
CORGI will then notify the
relevant Local Authority Building
Control (LABC) scheme
on members behalf

Scheme members only:
Call CORGI on 0870 88 88 777
or log onto:
www.corgi-notify.com
within 10 days

You must ensure that the
notification number
issued by CORGI is written
onto the Benchmark Checklist

Choose
Buildings Regulations
notification route

BUILDING CONTROL

Contact your relevant
Local Authority
Building Control (LABC) who
will arrange an inspection
or contact a government
approved inspector

LABC will record the data
and will issue a
certificate of compliance

IT IS A CONDITION OF THE
MANUFACTURERS WARRANTY

CORGI will record the data and
will send a certificate of
compliance to the property

THAT THE BENCHMARK
COMMISSIONING CHECKLIST IS
FULLY COMPLETED AND LEFT
WITH THE APPLIANCE

icos - Installation & Servicing

Technical Training
The Ideal Boilers Technical Training Centre offers a series
of first class training courses for domestic, commercial and
industrial heating installers, engineers and system
specifiers.
For details of courses please ring: ............. 01482 498 432

The code of practice for the installation,
commissioning & servicing of central heating systems

CERTIFIED PRODUCT
Manufactured under a BS EN ISO 9001:
2000 Quality System accepted by BSI

Ideal Boilers, P.O. Box 103, National Ave, Kingston upon Hull,
HU5 4JN. Telephone: 01482 492 251 Fax: 01482 448 858.
Registration No. London 322 137.
Ideal Stelrad Group pursues a policy of continuing
improvement in the design and performance of its products. The
right is therefore reserved to vary specification without notice.

Ideal Installer/Technical Helpline: 01482 498 663
www.idealboilers.com

users guide

icos
Your Ideal users guide

HE12, HE15, HE18, HE24
For installation guide see reverse of book
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 Ideal Boilers.

icos HE12, HE15, HE18, HE24
(Natural Gas Only)
Destination Countries: GB, IE

Introduction
The icos is a wall mounted, room sealed, super efficient
condensing boiler featuring full sequence automatic spark
ignition and fan assisted combustion.
Due to the very high efficiency, condensate is produced from
the flue gases and this is drained to a suitable disposal point
through the plastic waste pipe at the right lower rear of the
boiler. A condensate 'plume' will also often be visible at the
flue terminal.

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 CORGI registered installer.
In IE the installation must be carried out by a competent person
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.
It is essential that the instructions in this booklet are strictly
followed, for safe and economical operation of the boiler.

Electricity Supply
The appliance must be earthed.
Supply 230 V - 50 Hz.

The fusing should be 3A.

This appliance is intended to be connected to the supply via a
double-pole switch, having a 3mm contact separation in both
poles, serving only the boiler and system controls. Alternatively,
a 3-pin UNSWITCHED socket may be used.

HE12
HE15
HE18
HE24

G.C. Appliance No.
G.C. Appliance No.
G.C. Appliance No.
G.C. Appliance No.

41-397-95
41-397-83
41-397-84
41-397-85

z This appliance is not intended for use by persons (including
chilcren) 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.
z Children should be supervised to ensure that they do not play
with the appliance.
In cases of repeated or continuous shutdown a CORGI
registered installer or in IE a competent person should be called
to investigate and rectify the condition causing this and carry out
an operational test after each intervention on the device. Only the
manufacturers original parts should be used for replacement.

Minimum Clearances
Clearances of 165mm (6 1/2") above, 100mm (4") below, 5mm
(1/4") at the sides and 450mm (17 3/4") at the front of the boiler
casing must be allowed for servicing.
The minimum front and bottom clearance allowed when built into
a cupboard is 5mm.

To light the boiler (Refer to Frame 1)
1. CHECK THAT THE ELECTRICITY SUPPLY TO THE BOILER
IS OFF.
2. Set the mains on/off switch (A) to off and the CH thermostat
knob (C) to maximum.
3. Switch on the electricity supply to the boiler and check that all
external controls, e.g. programmer, room thermostat, etc are on.
4. Set the mains on/off switch to ON.
The boiler will commence the ignition sequence, supplying heat
to the system when required.

Operation

Important Notes

In normal operation the control unit display (F) will show the
codes:

z This appliance must not be operated without
the casing correctly fitted and forming an adequate seal.

O - Standby (no demand for heat)

z If the boiler is installed in a compartment then the compartment C - CH or DHW being supplied.
MUST NOT be used for storage purposes.
During ignition the LED (E) will flash.
z Under NO circumstances should any of the sealed components During normal running the LED will remain illuminated.
on this appliance be used incorrectly or tampered with.
Note. If the boiler fails to light after 3 attempts the fault code 'L' 'F'
z If it is known or suspected that a fault exists on the boiler
will be displayed.
then it MUST NOT BE USED until the fault has been
corrected by a CORGI registered installer or in IE a
Press and hold the reset button for 2 seconds then release. The
competent person.
boiler will repeat the ignition sequence. If the boiler fails to light
consult a CORGI registered installer or in IE a competent person.

All CORGI registered installers carry a CORGI ID card, and have a registration number. Both should be recorded
in the Benchmark Commissioning Checklist. You can check your installer by calling CORGI direct on 01256 372300.
Ideal Stelrad Group is a member of the Benchmark initiative 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

icos - Users

Control of water temperature

Boiler Overheat Thermostat

The boiler controls the central heating radiator temperature to a
maximum of 820C, adjustable via the CH thermostat knob (C).

This thermostat will shut down the boiler in the event of
overheating. Should this occur a fault code 'L' 'A' will be
displayed. Press the reset button (D) and the boiler will relight.
If the fault recurs turn off the boiler and consult a CORGI
registered installer or in IE a competent person.

Approx CH flow temperatures for the boiler thermostat settings
are:
Knob Setting

Flow Temperature
o
o
C
F

Minimum

Maximum

180

To shut down the boiler
1. For short periods
Set the mains on/off switch (A) to OFF.
2. For longer periods
Set the mains on/off switch (A) to OFF. Switch the electricity
supply to OFF. For longer periods the entire system should be
drained, inlcuding the domestic hot water supply.

Flame failure
Should this occur a fault code L-F will be displayed. Press the
reset button and the boiler will relight. If the fault recurs, turn off
the boiler and consult a CORGI registered installer or in IE a
competent person.

Condensate Drain
The condensate drain 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 CORGI
registered installer or in IE a competent person should be sought.

Escape of gas
To relight the boiler
Repeat the procedure detailed in 'To light the boiler'.

Should a gas leak or fault be suspected contact your local gas
supplier without delay.
Do NOT search for gas leaks with a naked flame.

Frost Protection
If no 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.

Cleaning

For longer periods the entire system should be drained.

To remove stubborn marks and stains use a damp cloth and mild
detergent.

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.

For normal cleaning simply dust with a dry cloth.

DO NOT use abrasive cleaning materials.

Maintenance
The appliance should be serviced at least once a year by a CORGI
registered installer or in IE a competent person.

BOILER CONTROLS
Legend
A

Boiler on/off switch

CH thermostat knob

Reset button

LED

Display

Condensate drain

CAUTION. To avoid the possibility of injury during the installation, servicing or cleaning
of this appliance care should be taken when handling edges of sheet steel components.

icos - Users

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 - TYPICAL NON PRODUCT FAULTS

Problem
1

Boiler is not working for
central heating or hot water.

Solution
•

Check there is power to the boiler – switch (A) in the ON position and ‘0 ’ displayed on the
controls.

•

If ‘0 ’ not displayed then not a boiler fault – contact your installer/service company.

•

Check external programmer is set to an ‘ON’ period and the relevant function selected i.e.
central heating or domestic hot water. Test by overriding the programmer by setting to
‘continuous.

•

Check room thermostat for central heating or the cylinder thermostat for domestic hot water,
are set at the required temperature. To test operation of either thermostat turn fully up. If no
response contact your installer.

Boiler is not working for
•
central heating or hot water
•
but attempts to fire by going
through 3 ignition attempts.
Display shows ‘L : F ’ (flashing). •

Press reset button (D) for 2 seconds to repeat ignition sequence.

Boiler is not working for
central heating or hot water
and the display shows ‘L:A ’
(flashing).

•

Press reset button (D) for 2 seconds, the boiler should then re-light. If fault recurs this
indicates an overheat condition. The boiler should be turned off and your installer contacted.

•

Check if ALL radiators have thermostatic radiator valves fitted. If they have contact your
installer.

Boiler is not working for
central heating or hot water
and the display shows ‘H:A ’
(flashing).

•

Check if ALL radiators have thermostatic radiator valves fitted. If they have contact your
installer.

Check gas supply (try another appliance – cooker/fire etc.) – If no gas supply then not a
boiler fault – contact gas supplier.
Check condensate pipe is not blocked or frozen. If blocked, clear blockage – if not possible
to check contact your installer.

Ideal Consumer Helpline
Tel: 01482 498660
www.idealboilers.com

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

Ideal Boilers, P.O. Box 103, National Ave, Kingston Upon Hull, HU5 4JN. Tel.
01482 492251 Fax. 01482 448858. Registration No. London 322 137.

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