BOSCH Water Heater, Gas Manual L0807391

User Manual: BOSCH BOSCH Water heater, Gas Manual BOSCH Water heater, Gas Owner's Manual, BOSCH Water heater, Gas installation guides

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6720607072-00.1

GWH-635-ES-N

- Natural Gas

GWH-635-ES-L

- Liquefied

Warning:
If the
followed exactly,
causing property
Do not store or
vapor and liquids
appliance.

Petroleum

information in this manual is not
a fire or explosion
may result
damage, personal injury or death.
use gasoline or other flammable
in the vicinity of this or any other

Improper
installation,
adjustment,
alteration,
service
or maintenance
can cause
injury or
property
damage.
Refer to this manual.
For
assistance
or additional
information
consult
a
qualified
installer,
service
agency
or the
supplier.
In the Commonwealth
of Massachusetts
product must be installed
gas fitter.
Upon
completion
instructions
should
appliance

by a licensed plumber

gas
this
or

of the
installation,
these
be handed to the user of the

for future reference.

(LP) Gas
What

to do if you smell

gas

•

Close gas valve. Open windows.

•

Do not try to light any appliance.

•

Do not touch any electrical
phone in your building.

•

Immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions.

•

If you cannot reach your gas supplier, call the fire
department.

•

Installation
and service must be performed
by a
qualified installer, service agency or the gas supplier.

switch;

do not use any

Index

Index
Warning

2
2.1
2.2
2.3
2.4
2.5

Appliance details
Features
GWH-635=ES Specifications (Technical data)
Unpacking the GWH-635-ES heater
General rules to follow for safe operation
Dimensions and Minimum installation clearances

4
4
4
5
6
7

For your safety

3
3.1
3.2
3.3
3.4
3.5
3.6
3.6.1
3.6.2
3.6.3
3.6,4
3.6.5
3.6.6
3.6.7
3.7
3.8
3.9
3.10
3.1 t
3.12

Installation
instructions
Introduction
Proper location for installing your heater
Heater pJacement and clearances
Mounting installation
Combustion air requirements
Venting
Vent material and specifications
Vent connections
Condensate drain tube requirements
Room sealed inst,'glation (Twin pipe)
Vertical terminations
Horizontal terminations
Exhaust vent configuration examples
Gas piping & connections
Measuring gas pressure
Water connections
Electrical connections
Cascading function
Recirculation application

8
8
8
8
8
9
t1
t1
t2
t3
13
14
t5
18
19
21
22
23
23
23

4
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8

Operation instructions
For your safety, read before operating your water heater
Power
Temperature selection
Use of optional remote control accessory
Operation
Reset button
Program button
Locked condition

24
24
24
25
27
27
27
27
27

5
5.1
5.2
5.3
5.4
5.5

Maintenance and service
Annual maintenance
Winterizing for seasonal use
Mineral scale build-up
Adjusting 002
Control board diagnostics

28
28
28
29
29
32

6
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8

Troubleshooting
Introduction
Burners do not ignite when hot water is turned on
Water is too hot
Water is not hot enough
Low water flow/pressure
Hot water temperature fluctuates at tap
Noisy burner/heater during operation
Error code diagnostics

33
33
33
33
33
34
34
34
36

Electrical

GWH-635-ES

9
9.1
9.2
9.3

Interior components
Interior cor',_ponents
Components diagram
Parts list

Protecting

Fifteen

diagram

Functional

scheme

diagram and parts list

the environment

Year Limited

Warranty

Warning

Do not store or use gasoline
or other flammable,
combustible
or corrosive
vapors and liquids in the
vicinity of this or any other appliance.

43
43
44
45

FCC:
This device complies with Part 1 5 of the FCC rules.

6 720 608

108

Warning

Operation is subject to the following two conditions: (1)
This device may not cause harmful interference, and (2)
this device must accept any interference received,
including interference that may cause undesired operation.

Water temperature over 125°F can
cause severe burns instantly or
death from scalds,
Children, disabled and elderly are
at highest risk of being scalded.
See instruction manual before
setting temperature at water
heater.
Feel water before bathing or
showering,
Temperature limiting valves are
available, see manual,

F_.I

6 720 608

108

Appliance details

Appliance

2.1

Features

details
Capacity
Maximum flow rate: 6.35 GPM (24 I/min) at a 45°F
(25°C) rise.

Parts
•

Touch pad interface

•

High power
emissions

control

pre-mix compact

burner with low NOx

Maximum output
142,968 Btu/h (41.8 kW)

•

Modulating
control

gas valve with constant

gas to air ratio

•

Modulating
temperature

water valve for improved
control.

Maximum input
175,000 Btu/h (51.2 kW)

comfort

and

Safety
•

Flame sensor (ionization)

•

Overheat

•

Temperature

•

Fan speed monitoring.

rod

High efficiency

•

Compact
space
supplied bracket.

•

Easily removable

efficiency

Btu/h

Selection

Stability:
burner

saver:

mounts

one-piece

Control

range: 100°F (38°C) - 140°F (60°C)

Default temperature:

life

heat exchanger
Ceramat

86.5%

(9.1 kW)

Temperature

High quality materials for long working

•

Recovery

31,131

limiter

Copper

in %

Min. Output

sensor

•

Efficiency

+/- 2°F (+/- 1°C)

Gas Requirement
on a wall

with

Gas connection

(inches) - 3/4" NPT

Inlet gas pressure
water flow rate)*

cover.

under

Features

•

Propane:

•

LCD Display

•

Natural Gas: 5"-

•

On/Off

•

Reset button

•

Program key (selectable

•

Failure codes for easy diagnostics

•

Diagnostic

•

Cascading

and temperature

Venting

function.

Accessories

•

Tankless Link: Allows two GWH-635-ES

Horizontal

vent termination

GWH-635-ES
Specifications
(Technical data)

Approved

in US/Canada

Measuring

gas

Water
•

Hot water connection

(inches) - 3/4" NPT

•

Cold water connection

•

Water valve material:
Sulfid)

•

Minimum water flow for activation:
(3 I/m)

•

Minimum recommended
(2.07 bar)

•

Connections:

(inches) - s/4" NPT
Polymer (PPS) (Polypropylene

kit (Part # 4TWHVK3S).

BOSCH
is constantly
improving
its
products,
therefore
specifications
are
subject to change without prior notice.

2.2

heaters to

for double the hot water volume

see

A condensate trap is integrated into the exhaust flue
gas collar of the heater, the supplied condensate drain
tube MUST be installed to it for proper removal of
condensate from the trap. Additional condensate traps
and drains may be necessary;
see chapter 3.6 for
Venting.

and repair

Optional
wireless
remote
control
accessory
remotely set temperature (Part # TSTAT2) .

a high hot

14" water column.

temperature)

•

(with

14" water column

* To measure
gas pressure,
pressure, chapter 3.8.

purposes

•

11"-

operation

control switches

mode for troubleshooting/informational

be linked together
(Part # TLINK) .

122°F (50°C)

Bottom

water

0.8 gallon/minute

pressure:

PSI

of heater

Combustion
•

NOx<55ppm

•

CO<300ppm

6 720 608

108

Appliance details

•

CO 2 level set from factory, see chapter

5.4.

•

Exhaust vent adaptor
provided)

•

Condensate

•

Combustion air inlet adaptor
ket provided)

•

Plastic decal shields for covering front cover screws
and control panel, installer should affix these decals
to the front of the unit after installation is complete.
See Fig. 3

Natural Gas.
LP Gas.

•

Converting the gas type can only be done by a certified
gas technician with a calibrated CO 2 analyzer.
Call Bosch Water Heating for conversion information.

Installation manual (replacement manuals can be
downloaded at www.boschpro.com)

•

Product

•

Energy Guide label.

Dimensions
•

Depth (in): 8 V2" (220 ram)

•

Width

(in): 15 3/4" (400 ram)

•

Height

(in): 23 1/2" (600 mm)

•

Weight:

47 pounds

(21 kg).

Gas types

Voltage
120 V AC (50/60

6 ft power supply cord

Idle - 40 mA
Operation

registration

return

Noise

•

Heating

< 50 db (A)

•

Solar/preheat

(with 3 screws

the

enclosed

is not approved

• Manufactured
(mobile)
mobile installation.

- < 2.5 A

and gasket

and gas-

card

and

The GWH-635-ES
for:

Amperage

4 screws

drain tube kit

Please complete
registration card.

Hz)

(with

homes,

RV's,

or other recirculating/pumping
backup

product

or designed
boats

or any

applications*

or high temperature

booster

use,

Safety

devices

•

Flame failure device (ionization

•

Pressure

•

Over heat prevention

Water

relief valve (supplied

flame rod sensor)
with heater)

(temperature

limiter).

resistant

IP X4 (protection

2.3

against water drops)

Unpacking

the GWH-635-ES

heater

Before installing the unit, be certain you have the
correct heater for your type of Gas - Propane or
Natural
Gas. Identification
labels are found on the
shipping box, and on the rating plate sticker which
located on the right side panel of the cover.

* This includes domestic hot water circulator pump loop
systems that may be installed in home hot water system
prior to installing this unit. An approved recirculation
design can be found in chapter 3.9. The use of a small
electric mini-tank water heater (4-6 gallon size) must be
used for this application and designed so the pump will
circulate the hot water in the mini-tank only and through
the building's
hot water
return
loop (timed
or
thermostatic
controlled
operation
of the pump is
commonly done). The GWH-635-ES
must be plumbed
in line before the mini-tank water heater and supplied
with cold water only. Contact Bosch Water Heating if
further instruction is needed.
To remove

front cover

•

Loosen the two Philips head screws located on front
panel (beneath plastic decal shields if they are
already attached, see Fig. 3)

•

Lift front cover panel upward and remove.

Plastic d
Fig. 2
A
B

:als

Rating plate sticker
Serialnumber
Type of gas

The box includes:
•

Pressure

•

Bracket for wall hanging the heater

6 720 608

108

relief valve (150 psi / 200,000

Btu rating)
Fig. 3

Remove

front cover

Appliance details

2.4

General

rules

to follow

for safe

•

operation
•

1. You must follow these instructions
when you
install your heater.
In the United
States:
The
installation must conform with local codes or, in the
absence of local codes, the National Fuel Gas Code
ANSI Z223.1/NFPA
54.
In Canada: The Installation must conform with CGA
B149.(1,2)
installation

INSTALLATION
codes.

CODES

and /or local

•

2. Carefully plan whereyou installthe
combustion
air supply and vent pipe
very important.
If not installed
accidents
can be caused by lack
monoxide poisoning or fire.

heater. Correct
installation are
correctly,
fatal
of air, carbon

•

3. When

the unit is installed

indoors

with

11. The heater must not be installed

in an unheated

area where temperatures will reach 36°F or lower. If
the heater is left in an area susceptible to such
temperatures,
refer to Section 5.4 on Winterizing.
•

12. In areas where water supply has a high mineral
content, a water softener is strongly recommended.
Damage to the water heater resulting from hard
water/scale deposits will not be covered under warranty.

•

13. In areas with warm inlet water (7O°F or greater),
increasing flow rate at low flowing fixtures may be
required to prevent outlet temperatures from
exceeding the desired temperature set point.

ROOM

SEALED (twin pipe) combustion air and venting,
permitted to be located in bathrooms, bedrooms
occupied rooms that are normally kept closed.
chapter 3.6. If the unit will be installed indoors
use indoor combustion
air, the place where
install the heater must have enough ventilation.
National
Fuel Gas Code and National

it is
and
See
and
you
The
Fire

Codes do not allow UNSEALED
gas fired water
heater installations
in bathrooms,
bedrooms
or any occupied rooms
See chapter 3.2 and 3.5.
your

heater.

kept

See

closed,

•

4. You must
VENTING.

•

5. The appliance and its gas connection must be leak
tested before placing the appliance in operation.
The appliance must be isolated from the gas supply
piping system by closing its individual manual gas
shutoff valve (not supplied with heater) during any
pressure testing at pressures in excess of V2 Psig
(3,5 kPa).

•

6. Keep water heater area clear and free from
combustibles
and flammable liquids, Do not locate
the heater over any material which might burn.

•

7. Correct gas pressure is critical for the optimum
operation of this heater. Gas piping must be sized to
provide the required pressure at the maximum output
of the heater, while all the other gas appliances are in
operation. Check with your local gas supplier and
see Chapter 3.7 Gas piping and connections.

•

8. Should overheating occur or the gas supply fail to
shut off, turn off the gas supply at the manual gas
shut off valve, on the gas line. Note: manual gas
shutoff valve is not supplied with the heater.

•

9. Do not use this appliance if any part has been
underwater.
Immediately
call a qualified
service
technician to inspect the appliance and to replace
any part of the control system and any gas control
which has been underwater.

•

10. Failure to install heater correctly may lead to
unsafe operation and void the warranty.

vent

normally

section

6 720 608 108

Appliance details

2.5

Dimensions

and Minimum

installation

clearances

FRONT

BOTTOM
_5 3;4"

3 3/_ 'F

(400)

_--_--_

_o
s

(K)

BACK
8 3_4'F

(220)

TOP
Fig. 4

Dimensions

1
2
3

Cover
On/Off switch
Reset button

4
5
6

LCD display
Program button
Temperature buttons

///////////////////////////////_

Fig. 5

Minimum

clearances

1 2"
1"

12"
Table 1 Minimum

6 720 608

108

clearances

Installation

instructions

Installation

3.1

Introduction

Please

these

instructions
3.3

instructions.

Failure

Heater

placement

and clearances

•

Damage or injury.

•

Improper operation.

The GWH-635-ES
is design certified for installation on
a combustible
wall (see 3.4 Mounting
installation)
provided
the floor covering
below
the heater
is
noncombustible.
For installations in an alcove or closet,
maintain the minimum clearances to combustible
and

•

Loss of warranty.

non-combustible

instructions

may result in:

If you are unable to perform the tasks required to install
this heater properly, please contact a locally licensed
plumber or gas technician.
Please
contact
Bosch
Water
Heating
with any
questions.

3.2

Proper location
heater

for installing

your

Carefully select the location of the water heater. For
your safety and for proper heater operation, you must
provide combustion
air to the heater and a proper
exhaust vent system.
Follow the guidelines below:
•

1. Locate the heater where
venting, gas and
plumbing connections
are feasible and convenient.

•

2. The hot water lines should be
energy.
Centrally
locating
the
recommended
to keep hot water
even throughout
the structure. It
have hot water lines insulated.

materials listed below. See also Fig. 5.

A. Top 12 inches (306 ram)
B. Front 1 inches (25 mm)
C. Back 0 inches
D. Sides 1 inches (25 mm)
E. Bottom 12 inches (306 ram)
Clearances from any exhaust vent pipe are dependent
upon the clearance requirements of the stainless steel
vent pipe manufacturer.
Single wall stainless steel
(AL29-4C)
vent pipe (vent type rated for Category Ill
appliances)
must be used when exhaust venting this
appliance. See 3.6 Venting.

3.4

Mounting

installation

kept short to save
water
heater
is
distribution
times
is always best to

Front

cover

should

removed

(see

instructions on page 5) in order to inspect
components visually.
•

Secure the wall mounting
heater to a wall surface.

bracket provided

with the

If wall is sheathed with plasterboard, it is recommended
that two support boards, either 1"x4" or 1/2" (minimum)
plywood first be attached across a pair of studs. Then
attach the heater's bracket to the upper support board.
The heater should be kept level on the wall surface. See
Fig. 6.

6720608108

Installation

pitch down towards
horizontal length.
Single

termination

instructions

1/4inch for every foot of

pipe method:

Although it is permissible to draw combustion
air from
the inside, it is not the manufacturer's
recommended
installation method. Always install a 3 inch elbow on the
top of the combustion
air inlet adaptor to prevent
foreign objects from falling into the unit.
If a single pipe installation is utilized, follow guidelines
below for providing adequate combustion
air for the
water heater as well as any other appliances that may
consume air in the space. Always follow local codes if
they are more stringent.

Fig. 6

3.5

Mounting

the heater

Combustion

air requirements

Fig. 7

Single pipe installation

The GWH-635-ES

Twin pipe method:
The GWH-635-ES
is designed as a sealed combustion
appliance. It is recommended
that the combustion
air
be provided by a dedicated 3" or 4" pipe to the outside.
The combustion
air pipe may be aluminum flex, PVC or
any other rigid or semi rigid sealed 3" or 4" pipe. The
combustion
air inlet, whether terminating vertically or
horizontally, must be located in such a manner as to
provide a minimum 3 foot clearance from the exhaust
vent terminator. See Fig. 17 Letter L
The maximum length of the combustion
air inlet is 26
feet with one elbow. Subtract
2.5 feet for additional
elbows. Maximum number of elbows permitted is 3.
Horizontally
terminating
combustion
air pipes must

6 720 608

108

water heater holds cold water in its

copper heat exchanger and water valve when not in use.
Because of this, any cold air that comes through the
unit's vent pipe could freeze and damage these
components. This Installation Manual specifies the
minimum vertical vent pipe and the amount of
combustion air required for this unit. When all
requirements are followed, the unit will operate properly
and safely. However, there may still be a risk of freezing
due to negative draft if the other combustion appliances
in the building are not supplied with sufficient
combustion air. A wood stove or furnace can pull its
combustion air from the heater's vent pipe, allowing the
cold incoming air to freeze the cold water in the heat
exchanger. Supplying more combustion air for all
combustion appliances is the solution. A HVAC
specialist should be consulted to design solutions for
providing more combustion air. Observe the following
guidelines:
Installations in structures that have been tightly
constructed
(air infiltration rate of 0.40 ACH or less)
must be provided with combustion
air per the National

Installation

instructions

Fuel Gas Code. Consult a HVAC specialist if your air
infiltration rate is questionable.
The space must have two permanent openings, one
commencing within 12 inches of the top and one
commencing within 12 inches of the bottom of the
enclosure. Each opening must have a minimum free
area of one square inch per:
1000 Btu/hr
•

if all air is taken from inside the building

2000 Btu/hr if all air is taken from the outside
horizontal ducts

• 4000 Btu/hr if all air is taken from the outside by
direct openings or vertical ducts.
Or the space must be provided with one permanent
opening or duct that is within 12 inches of the ceiling of
the enclosure. This opening must have a minimum free
area of one square inch per:
•

3000 Btu/hr if all air is taken from the outside
direct opening or vertical duct.

by a

Louvers, grills and screens have a blocking effect. If the
effective free area is not known, increase the sizes of
your openings by 300°/o if your louvers are wood and by
350/0 if your louvers are metal. Refer to the National Fuel
Gas Code for complete information.

6 720 608

108

Installation

3.6

instructions

permitted in the total vent length), or subtract 11/4
feet for every 45 ° elbow used. Horizontal sections of
vent must pitch upwards from heater _/4" for every foot
of horizontal length, to prevent the pooling of
condensate, and be supported at 4 foot intervals with
overhead hangers. See Table 2.

Venting

Exhaust

Intake

3or4
inches

Vent

3 feet

Sealed single
wall stainless

elbow

stee_ (AL29-40)

Sealed
_l_rn_num flex,

26 leet w_th

3or4
inches

Vent

26 leet wr_}l
1 90°

1 90 ° elbow

1 90_
elbow

PVC or any
other rlg_d or
semi rigid p_pe

TaMe 2 Venting specifications

Minimum exhaust vent size and length

The minimum
3 feet.
The use

3.6.1

Vent material

Minimum

of a 90

vent length

degree

elbow

equivalent

to 21/2 ft in vent length,

The

use

equivalent

Fig, 8

exhaust

degree

elbow

is
is
is

to 1 1/4ft in vent length,

vent/ength

and specifications

Establish vent clearances that comply with the vent
manufacturer's
specifications.
In all cases follow local
codes,

Note: Listed thimbles or collars are necessary to pass
through wall and ceiling partitions. If the vent system
passes through combustible
areas where the vent
clearance requirements cannot be maintained, it is
permissible to chase straight sections of sealed 3 inch
single wall vent through 4 inch (or greater) Type-B vent.
The distance to combustibles
using this chase
technique is 1 inch (check local codes).
Reduce

maximum

length 21/2 ft for
each 90 elbow after
the first one and 1 1/4
ft for each 45 elbow,

Ventlengths

Fig. 9

The appliance should be located as close to the point
of termination as possible. The maximum vent length is
26 feet (8 m) with one 90 degree elbow. Subtract 2V2
feet from the total vent length for each additional 90 °
elbow used (a maximum
of three 90 ° elbows are

Vent

6 720 608

108

Maximum

vent and combustion

air lengths

material

The GWH-635-ES
requires 3 or 4 inch sealed single
wall stainless steel vent pipe (AL29-4C),
Use of any
other vent material will void the manufactures warranty

Installation

instructions

and may result in a hazardous condition.
For specific
questions concerning vent material, specifications,
usage or installation, contact the vent manufacturer
directly.

page 33. Correct
before operating.

3.6.2

the problem

and then reset the heater

Vent connections

Exhaust vent connection

Z-flex

www.z-flex.com
800-654-5600

ProTech Industries

www.protechinfo.com
800-766-3473

Heat-Fab

www.heatfab.com
800-772-0739

Table 3 Vent manufacturer

contact

inforrnation

•

Attach the flue gas exhaust accessory (8 705 504
137) to the top of the unit (position 1) using the 4
screws and gasket provided.

•

Insert single wall stainless steel vent pipe into the
exhaust vent adapter 1.5" and tighten the clamp ( Fig.
10 position 2).

Note: 3 to 4 inch increaser
pipe.

required when using 4 inch

Note; Failure to fully insert vent pipe and tighten clamp
may cause flue gas leakage or condensate damage that
is not covered under the manufacturer's
warranty.
3" Venting
3" Hor_ont al

2SVSTB03

FSTB3

_390 TEE

2SVSRCF03

FSRC3

530001

90°
Condensate
Drai_ Tee

2SVEVWCF03

FST3 &
FSDF3

93PPLSTEE

Horizont a_
Condensate
Drain

2SVEDWCF03

FSHDT3

9321

2SVSEVDP03

N/A

2SVEDTK

N/A

7000TUBE

temlinat_on

3" Vert_ca_
termination

Vertical

Condensate
Dra_n

Fig. 10
Condensate
Dra_n Tube

2SV10304

FSO304TI

9374

2SVSRTF04

FSTB4

g490TEE

2SVSRCF04

FSRC4

54000J

90°
Condensate
Dialn Tee

2SVEV'C/CF04

FST4 &
FSDF4

9416 &
9417D

Hodzor/tal
Condensate
Drain

2SVEDWCF04

FSHDT4

9421

2SVEVDP04

FSUCD4

N/A

2SVEDTK

N/A

7000TUBE

(Requited)

4" Hor_ont _l

The combustion air inlet accessory can be connected
either to the top right or left of the appliance, The
unused side must be sealed.
•

Attach the combustion air inlet accessory (8 705
504 11 5) to the top of the unit (position 3) using the
3 screws and gasket provided.

•

Install combustion
air pipe over the air inlet accessory. If using flexible piping, secure with a clamp
(position 4, not included).

termination

4" Vert_ca]
termination

vent connection

Combustion air inlet connection
4" Venting

3" to 4"
Jrloleaset

Exhaust

Vertical

Condensate
Dra_n

Condensate

Dra_n Tube

Table 4 Approved
vent termination
and condensate
drain part numbers (subject to change)

Vent Safety System
The GWH-635-ES will shut down if inadequate exhaust
venting is detected or a lack of combustion air is
provided to the unit. See troubleshooting section on

Fig. 11

Combustion

air inlet connection

6 720 608 108

installation

3,6.3

Condensate drain tube requirements

instructions

Exhaust collar condensate drain installation

Note: Condensate must be disposed of according to
local codes.
Note: Do not install condensate drain in areas where it

(supplied with heater)

may freeze.

•

1. Install condensate

The condensate

drain tube kit must be used for all

installation types. Failure to properly install condensate drain will void the warranty.
•

•

When installing the condensate drain tube kit on the
exhaust collar (see diagram below), be sure to form a
trap by means of a 3 *' (76.2 ram) loop partially filled
with water. This loop must be as low as possible to
allow proper drainage of condensate. The supplied
tube is 3/8" ID high temperature silicone and must be
attached to the condensate port on the exhaust collar
with its supplied gear clamp (first remove brass
screw from port).
To increase tube length, connect vinyl tubing (not
supplied with heater) to the supplied tube. Do not
reduce tubing diameter when using connector or
additional tubing.
The condensate must be disposed
local regulations.
Condensate

of according

drain as close to heater as

possible.
2. Use 3/8" ID high temperature silicone tubing to
connect to condensate drain port. Do not use copper
piping for any portion of the condensate drain.
3. Form a condensate trap by means of a 3" loop and
fill bottom of loop with water.
4. To increase the tube length, connect to end of the
high temperature silicone tubing with vinyl tubing,
PVC or CPVC pipe. Do not reduce the internal
diameter at any point.
5. Dispose

of condensate

according

to local codes.

_RAIN

CAP

STORM COLLAR
TOPSUPPORT

port on exhaust collar

FLASHING

1. Remove brass hex head
screw
AIR SPACE

TO DRAIN-DISPOSE
OFCONDENSATE
ACCORDING TO
LOCALCODES

2. Fit tube with
gear clamp

3. Loop size and location. Coil tube into 3" loop
with nylon tie (don't crimp tubing) and fill bottom
of loop with water
Fig. 12

Exhaust

collar condensate

drah_ installation

Note: No part of supplied silicone tube should be
installed above condensate tapping or improper drainage may occur. (see Fig. 12).
External
plied)

condensate

An additional
installed

drain

installation

external condensate

under the following

r_7_808_7.!

Fig. 13

3.6.4

Required
condensate
(Combustion
air piping
Room

(Twin

pipe)

drain must be

conditions:

Vertical terminating

•

Horizontal terminating vent installations
total vent length is greater than 5 feet

•

Vent installation where any section of the exhaust
vent pipe passes through an unconditioned
space.

vent installations
where the
•

Although it is permitted to draw combustion air from
inside the structure in warm climates, the recommended

108

installation

drain
h_stallation
not shown)

(not sup-

•

6 720 608

sealed

method is to provide combustion

air through

Installation

instructions

a 3" or 4" pipe from the outside. See Chapter
more direction on combustion air.
•

3.5 for

Vent terminations
•

No pipejoints other than the termination connections
should be exposed to the outdoors. See vent manufacturer instructions for details.

•

Use of two 90 ° elbows (candy-cane) is an acceptable termination for combustion air intake from the

To reduce pressure differentials between the exhaust
and combustion air intake, it is recommended that
both terminators exit on the same plane. See Fig. 14
for an example horizontal twin pipe termination and
Fig. 15 for the vertical twin pipe termination example.

roof. See Fig. 15 for an example.
•

Screening (no smaller than 1/4" mesh) is recommended on candy cane termination.

•

Exhaust should terminate above and must be a minimum of 3 feet from must intake termination.

•

The exhaust vent must terminate

above the roof sur-

face with an approved vent cap not less than 3 feet
(0.6 m) above the highest point where it passes
through the roof and at least 2 feet (0.6 m) higher
than any vertical wall or similar obstruction within 10
feet (3.1 m). See Fig. 16 and Table 5.
Fig. 14

Horizontal

twin pipe termination

FROM HEATER

ABOVE THE ROOF

............

Fig. 16 Vertical
vent
termh?ations
clearances
(Combustion air piph_g not shown)

Fig. 15
3.6.5

Vertical twin pipe termh_ation
Vertical

Horizontal

terminations
Flat to 6/12

t .0

0.30

6/12 to 7/12

t,25

0,38

Over 7/12 to 8/12

t .5

0.46

Over 8/12 to 9/12

2.0

0.61

Over 9/12 to 10/12

2.5

0,76

Over 10/12 to 11/12

3.25

0.99

Over 11/12 to 12/12

4.0

1.22

Over 12/12 to 14/12

5.0

t.52

Over 14/12 to 19/12

6.0

1,83

Over 16/12 to 18/12

7.0

2.13

Over 18/12 to 20/12

7.5

2.27

runs

Any gas vent section that is greater than 45 degrees
from the vertical is considered horizontal. Horizontal
sections must slope upwards from heater at least 1/4
inch for every foot of its horizontal length and be properly supported to allow condensate to be collected by
condensate drains.

Table 5 Termh?ation heights

at various roof pitches

6 720608 108

Installation

Over 20/12 to 21/12
Table 5 Termh_ation
Interior

masonry

8.0
heights

izontal vented gas fueled equipment, the installing
plumber or gasfitter shall observe that a hard wired
carbon monoxide detector with an alarm and battery
back-up is installed on the floor level where the gas
equipment is to be installed. In addition, the installing
plumber or gasfitter shall observe that a battery operated or hard wired carbon monoxide detector with an
alarm is installed on each additional level of the dwell-

2.44

at various roof pitches

chimneys

The single wall stainless steel exhaust vent pipe must
be permanently mounted inside the masonry chimney.
The masonry chimney may have to be tile or metal lined
before the insertion of the gas vent pipe; check local
codes for clarification. You may not vent any other fuel
burning appliances into any free space remaining in the
chimney. The vent terminator must extend at least 3 feet
(0.9 m) above where the chimney meets the roefline and
at least 2 feet (0.6 m) higher than any vertical wall or
similar obstruction within 10 feet (3.1 m). The top of the
chimney must be sealed to prevent rain water or other
elements from entering the chimney.
Exterior

masonry

ing, building or structure served by the side wall horizontal vented gas fueled equipment. It shall be the
responsibility of the property owner to secure the
services of qualified licensed professionals for the
installation of hard wired carbon monoxide detectors.
a. In the event that the side wall horizontally vented
gas fueled equipment is installed in a crawl space or
an at tic, the hard wired carbon monoxide detector
with alarm and battery back-up may be installed on
the next adjacent floor level.
b. In the event that the requirements of this subdivision can not be met at the time of completion of
installation, the owner shall have a period of thirty
(30) days to comply with the above requirements;
provided, however, that during said thirty (30) day
period, a battery operated carbon monoxide detector
with an alarm shall be installed.

chimneys

Refer to the National Fuel Gas Code and consult a local
venting HVAC contractor.
climates.

3.6.6
•

Net recommended

in cold

Horizontal terminations

For horizontal

vent runs less than 5 linear feet, the

entire vent run must pitch down to termination 1/4"
per foot to eliminate the danger of rain from entering
the venting system.
•

The exhaust vent must terminate
penetrates the outside wall.

•

An approved vent terminator
Table 4 for known approved
terminations.

immediately

•

Install an additional condensate drain (not supplied)
if the total straight vent length is greater than 5 feet
or if the exhaust vent pipe passes through an
unconditioned
space.

•

Terminating
termination

•

Fig. 1? and table 6 show the required clearances
the vent termination. Follow local codes if more

for

3.6.6.1 Attention
residents
of Massachusetts:

of the Commonwealth

In the Commonwealth
of Massachusetts
the following
regulation went into effect on 12/30/2005:
(a)For all side wall horizontally vented gas fueled equipment installed in every dwelling, building or structure
used in whole or in part for residential purposes, including those owned or operated by the Commonwealth
and where the side wall exhaust vent termination is less
than seven (7) feet above finished grade in the area of
the venting, including but not limited to decks and
porches, the following requirements shall be satisfied:

1. INSTALLATION OF CARBON MONOXIDE DETECTORS. At the time of installation of the side wall hor-

108

APPROVED

CARBON

MONOXIDE

DETECTORS.

Each carbon monoxide detector as required in
accordance with the above provisions shall comply
with NFPA 720 and be ANSI/UL 2034 listed and IAS
certified.
3,

SIGNAGE. A metal or plastic identification plate shall
be permanently mounted to the exterior of the building at a minimum height of eight (8) feet above grade
directly in line with the exhaust vent terminal for the
horizontally vented gas fueled heating appliance or
equipment. The sign shall read, in print size no less
than one half (1/2) inch in size, "GAS VENT
DIRECTLY BELOW. KEEP CLEAR OF ALL
OBSTRUCTIONS".

INSPECTION. The state or local gas inspector of the
side wall horizontally vented gas fueled equipment
shall not approve the installation unless, upon
inspection, the inspector observes carbon monoxide
detectors and signage installed in accordance with
the provisions of 248 CMR 5.08(2)(a)1 through
4.

the intake air piping above the exhaust
is not recommended.

stringent.

6 720 608

once it

must be used. See
horizontal vent

instructions

(b) EXEMPTIONS:
The following equipment
exempt from 248 CMR 5.08(2)(a)1
through
4:

1.The equipment listed in Chapter 10 entitled
"Equipment Not Required To Be Vented" in the most
current edition of NFPA 54 as adopted by the Board;
and
2. Product approved side wall horizontally vented
gas fueled equipment installed in a room or structure
separate from the dwelling, building or structure
used in whole or in part for residential purposes.
(c) MANUFACTURERS
REQUIREMENTS
- GAS

Installation

instructions

EQUIPMENT

VENTING

SYSTEM

REQUIRED.

When the manufacturer of Product Approved side
wall horizontally mounted gas equipment provides a
venting system design or venting system components with the equipment, the instructions provided
by the manufacturer for the installation of the equipment and the venting shall include:
1. Detailed instructions for the installation of the venting system or the venting system components:
and
2. A complete parts list for the venting system design
or venting system.
(d) MANUFACTURER
REQUIREMENTS
- GAS
EQUlPMENTVENTING
SYSTEM NOT PROVIDED,
When the manufacturer of a product approved side
wall horizontally vented gas fueled equipment does
not provide the parts for the venting of flue gases, but
identifies "special venting systems, '_the following
requirements shall be satisfied by the manufacturer:
1. The referenced _special venting system" instructions shall be included with the appliance or equipment installation instructions;
and
2. The _special venting systems" shall be product
approved by the Board, and the instructions for that
system shall include a parts list and detailed installation instructions.
(e) A copy of all installation instructions for all products approved side wall horizontally vented gas
fueled equipment, all venting instructions, all parts
lists for venting instructions, and/or all venting design
instructions shall remain with the appliance or equipment at the completion of the installation.

6 720 608

108

Installation

Recommended

exhaust vent terminator

instructions

clearances

Fig. 17
Description
Directly below an opening; operable windows, doors and any nonmechanical fresh air openings

distance

36 in (twin pipe installation)
48 in (single pipe installation)

Below a gutter, sanitary pipework or eaves

24 in

Below a gutter, sanitary pipework or eaves, protected by metal
shielding

12 in

From any internal corner

12 in

Above ground or snow pack

12 in

Above a paved sidewalk

Tab/e

Minimum

? ft

From an opposing wall or structure facing the termination

24 in

From the relief valve of a gas regulator

36 in

From a terminator facing a terminator

48 in

Vertically between two exhaust vent terminators on the same wall

60 in

Horizontally between two exhaust vent terminators on the same wall

12 in

Horizontally and vertically from combustion air inlet of a twin pipe
system

36 in

From the gravity combustion air inlet any other equipment

48 in

From any external comer

12in

Horizontally from an openingl operable windows, doors and any nonmechanical fresh air openings

12 in (twin pipe installation)
48 in (single pipe installation)

Vertically from a wall, roof slope, or obstruction (venting through a fiat
or pitched roof)

see Chapter 3.6.5

* Subject to local codes and anticipated snow level
** Other equipment that operates with a mechanical air inlet may require greater distances, reference manufacturer's instructions
NOTE: terminating exhaust vent under a deck is not recommended

6 720 608 108

Installation

3,6.7

instructions

Exhaust

vent configuration

examples
RAIN CAP _.

Supporting

the exhaust

vent system

STORM COLLAR
SILICONE SEAL

FLASHING
MI_IMUM

ABOV

GR©U

CHIMNEY

MAY BE INSULATED
IF NECESSARY

HORIZONTAL
1/4" RISE/F1

RUN

Fig. 18 Horizontal side waft venting installation
(combustion air piping not shown)
Note: Pitch venting up 1/4" per foot to termination and
add additional condensate drain for vent runs longer
than 5 linear feet.
Note: Pitch venting down 1/4" per foot to termination
for vent runs less than 5 linear feet.

ELBOW
TO DRAIN - DISPOSE
OF CONDENSATE
ACCORDING TO
LOCAL CODES

Note: For horizontal terminations, venting must
terminate once it penetrates to the outside of the
structure. There should be no sections of vent pipe
exposed to the outdoors.
_

P_IN

APPLIANCE

[

CAp

Fig. 20

Fig. 19

Vertical venting installation
piping not shown)

ADDI FIONAL
DRAIN TRAp

(combustion

Vertical venting insta//ation - Interior masonry
Chimney (combustion
air piping not shown)

air

6720608108

Installation

3.7

Gas piping

& connections

]_!

Before connecting
the gas supply, check the rating
plate on the right side of the heater to be sure that the
heater is rated for the same gas to which it will be
connected.
In the United States: The installation must conform with
local codes or, in the absence of local codes, the
National Fuel Gas Code ANSI Z223.1/NFPA
54.
In Canada: The Installation must conform to CGA B149
INSTALLATION
CODES
and/or
local
installation

instructions

manufacturer's
sizing tables to determine
the pipe
diameter necessary to accommodate the 175,000 BTU
demand of the heater. If there are more gas drawing
appliances on the line, size the gas line according to the
total maximum amount of BTU draw for all appliances.
Note: Under sizing the gas line
output and improper operation.
procedure
to confirm
gas
pressure must be confirmed at

may result in diminished
See chapter 3.8 for the
pressure.
Proper
gas
time of installation.

codes,

Inlet gas particle

screen

Gas piping
t

_720607072.18,_j

Fig. 21

GAS CONNECTIONS
•

Install a manual gas shut off valve on the gas supply
line.

•

Install a union when connecting

•

The minimum diameter required
connector used is 3/4" ID.

gas supply.

•

National Fuel Gas Code requires that a sediment
trap (drip leg) be installed on gas appliances not so
equipped. The drip leg must be accessible and not
subject to freezing conditions. Install in accordance
with the recommendations
of the serving
gas
supplier.

for any appliance

Once connections are made, check for gas leaks at all
joints. Apply some gas leak detection solution to all gas
fittings. Bubbles are a sign of a leak. A combustible gas
detector may also be used to detect for leaks.

GAS LINE SIZING
The gas supply piping should be sized for a maximum
draw of 175,000
BTUH. Measure the length of gas
supply line and use the tables in Fig. 22 or the gas line

6 720 608

108

Installation

instructions

FOR NATURAL GAS
Maximum Capacity of pipe in Cubic Feet of Gas per Hour for Gas Pressure of 0.5 Psig or less and a Pressure
of 0.3" in Water Column (0.75mbar).(Based
on a 0.60 Specific Gravity Gas) Btu numbers given in thousands.

Follow boxed numbers for piping just one GWH-635-ES
will handle 190,000
btu's (55.7 kWh). For multiple
to applicable chart below.

drop

(example: 3/4"B,I. Natural Gas pipe for 20 ft (6.1m).

appliances

combine

the total btu input load and then refer

Nominal
Iron

Length

Pipe

Intemal

Size,

Diameter

inches

of Black Iron Pipe, Feet

100

125

150

175

200

1/4

0.364

3/8

0.493

1/2

0.622

132

1.049

520

350

285

245

215

195

180

170

160

150

130

120

110

100

59
225

55
210

o824r278 1 o115213o 115105g, 190 84 79 72
1.380

1050

?30

590

500

440

1 1/2

1.610

1600

1100

890

760

670

2.06?

3050

2100

1650

1450

1270

370

I 350

320

305

275

64
250

610

560

530

490

460

410

380

350

320

1150

1050

990

930

8?0

780

710

650

610

400

Length of F_exibleOorTugated Stainless Steel Tubing (CSST}, Feet
Tube
size,
inches

EHD*
10

1/2

18EHD

3/4

23EHD

161

116

30 EH_
3?EHD

639

456

374

144
292

131
26?

* EHD = Equivalent Hydraulic Diameter. The greater the
F_

162
r.325
/

value of EH D, the greater the gas capacity of the tubing.

FOR LP GAS
Maxirnum Capacity of Pipe in Thousands of BTU per Hour of Undiluted Petroleurn Gases (at 11 inches Water Column Inlet
Pressure)

(Based

on a Pressure

Drop of 0.5 Inch Water

Column).
* EH D = Equivalent Hydraulic Diameter. The greater the
value of EH D, the greater the gas capacity of the tubing.

Length of FlexiMeOolrugated StainlessSteel Tubing (CSST),Feet

Nominal
Tube

iron

Blackiron

pipe

Length of Pipe, Feet

Inches
1/2
3/4
Ill

Pipe

size
inches

100

125

150

200

I 291

200

160

137

122

110

4181336
787 632

287
54

255
480

231
434

197
372

175 I 155
330
292

140
265

608
45

lr2

120
227J

[_
1 1/4

Maximum

Capacity

Semi-Rigid

(flexible,

Liquefied

Petroleum Gases (at 11 inches

Water Column Inlet Pressure).
(Based

on a Pressure

* Source

National

Drop of 0.5 Inch Water
Fuel

Z223.t

- No Additional

ordinary

number

Gas

Code

Allowance

NFPA

Column)
54,

is necessary

18EHD

129

23 EH_
30 EHD

521

365

151
1297

131
256

118
227

107
207 I

37EHD

971

661

528

449

397

359

non

corrugated) Tubing in Thousands of BTU per Hour of
Undiluted

EHD*

ANSI
for an

Copper
Length o1Tubing, Feet

Outside
diameter
Inch

3/8

1/2

-_[]131

107
32912161811

lOg

145

131

121

112

104

of fittings

Fig. 22

6 720 608

108

Installation

3.8

Measuring

Confirm

proper gas pressure

instructions

gas pressure
upon installation.

Connecting Manometer
•

Shut off gas supply at installer supplied

•

Remove front cover and locate
measuring point (see Fig. 24).

•

Loosen screw inside left test point fitting (do not
remove) and connect manometer tube to test point.
Remove screw completely if correct size adapter is
available.

Static

Pressure

shutoff valve.

inlet gas pressure

Fig. 24

Gas pressure

measuring

(left tapping)

Test

•

Turn gas supply back on.

•

Operate all other gas appliances (except heater) on
same gas piping system at maximum output.

•

Record

static gas pressure

reading in table 7.

Table 7

Operating

Pressure

Test

•

ON/OFF

switch ill position

•

Press and hold "Program" (P) button and turn ON/
OFF switch to ON position.

HIGH ALTITUDE

OPERATION

OFF (O).
Natural
Gas:

Liquid
Propane:

no
modification

CO 2 adjustment with flue
gas analyzer required See
section 5,4 for instructions.

For operation at
eJevafions
above 2,000 ft
(610 rn) the
equipment
ratings shall be
reduced at the
rate ot 4% for
each 1,000 ft
(305 rn) above
sea level

Not approved

Fig. 23
•

As soon as '188' is displayed, release "Program"
dE>, button and the display should read P2.

•

Press LZ5 until P1 appears.

Table 8

Note: While
in this mode the appliance
will run
constantly at maximum power and allow maximum water
flow.
•

Turn on a high
and heater will
open more hot
Press _5 until

•

Record lowest
table 7.

volume of hot water (at least 4 gpm)
ignite. If heater display reverts to P2,
water fixtures to allow sufficient flow.
P1 reappears on display.
operating

gas

pressure

reading

Gas pressures lower than 5" W.C. for Natural Gas or
11" W.C. for LPG will result in insufficient degree rise
to the hot water being used, possible error code faults
and must be corrected.
See Gas Connections,
chapter 3.7.

6 720 608

108

Installation

3.9

instructions

Water

or flush
heater.

connections
•

the lines

before

connecting

to the water

Full port shutoff valves should be installed on both
the cold water supply and hot water outlet lines to
facilitate servicing the heater (see Fig. 26).

Note; If water flow or pressure is low, or heater does
not ignite, check the water inlet filter screen for debris
(see Chapter 5.1).
Connecting

the pressure

relief valve (PRV)

A listed pressure relief valve supplied with the heater
must be installed at the time of installation. No valve is
to be placed between the PRV and the
reducing coupling or other restriction may
in the discharge
line. The discharge
line
minimum of 4" above a drain and installed
•

When facing the heater, the 3/4"cold inlet connection
is on the bottom right and the hot connection is on
the bottom left. Centrally locating the water heater is
recommended to keep hot water distribution times
even throughout the structure.

heater. No
be installed
must be a
such that it

allows complete drainage of both the PRV and the line.
The location of the PRV must be readily accessible for
servicing or replacement, and be mounted as close to
the water heater as possible. See Fig. 26. To install the
PRV, a suitable fitting connected
to an extension on a
"T" fitting can be sweated to the hot water line.
Support all piping.

&
(not supplied with
heater)

HOT

COLD

Fig. 25
1
•

The use of unions when connecting both water pipes
to the cold and hot water connections
is required.
This will facilitate any necessary servicing.

•

Plastic or PEX type plumbing line materials are not
suitable for connecting directly to the water heater.

•

Although water piping throughout the building may
be other than copper, we recommend that copper or
suitably rated stainless steel flex line piping be used
for the water connections
for 1.5' on either side of
the water heater (follow local codes if more strin-

Fig. 26

!
P/urrlbing

connections

and pressure

(with

isolation

va/ves)

refief valve

gent).
•

Never sweat any rigid piping directly to or beneath
the water connections,
as damage can occur to the
internal water valve from heating of the pipe.

•

Keep water inlet and outlet pipes to no less than 3/4"
(19.O5mm) diameter to allow the full flow capacity.

•

If the cold

and hot connections

to the heater

reversed, the heater will not function.
are no loose particles

are

Be certain there

or dirt in the piping.

Blow out

6 720608

108

Installation

3.10

Electrical

connections

Ariston
Fig, 27

The GWH-635-ES
requires an electrical power supply
from a 120VAC / 60Hz circuit (with a dedicated outlet)
and must be properly grounded.
A means for switching off the 120VAC power supply
must be provided.
The heater is wired as shown in the wiring diagram
(chapter 7, Fig. 44).

3.11

Cascading

function

Cascading
enables the appliance to be connected
in
parallel with up to 4 appliances. An appliance in this
system will only start, if it gets a signal from the
appliance before it. That means, the appliance works
always as a Master to the next appliance and always as
a Slave to the one before.
For more detailed information
the instructions
•

instructions

supplied

1
2
3
4
5

Recircutation

Minitank

appfication

Full port isolationvalve
Circulator
Check valve
PRV
Expansiontank

The use of a small electric
gallon size)
designed so
the mini-tank
only. Timed
the pump is
be supplied
before the

mini-tank water

heater (4-6

should be used for this application
and
the pump will circulate the water through
and the building's hot water return loop
or thermostatically
controlled operation of
commonly done. The GWH-635-ES
must
with cold water only and plumbed in line
mini-tank water heater. Contact
Bosch

Water Heating

if further information

is needed.

about this feature, consult

with the accessory:

7 709 003 617.

3.12

Recirculation

application

Since
recirculation
through
the
heater
is
not
permissible, the following drawing is provided to outline
a proper recirculation
application
using the Aquastar
water heater with an Ariston minitank water heater. This
schematic is for illustration only and must not be used
for actual installation without appropriate
engineering
and
technical
advice
from
a properly
licensed
professional
in the locality where the installation
is
made.

6 720 608

108

Operation instructions

Operation

instructions

°©

42)

\
L_

672O6O7072-21,2JS

Fig. 28
1
2
3
4
5
6

On/Off switch
Reset button
Program" _
" button
Increasingtemperatureselector
Decreasing
temperature selector
LCD display

4.1

For your safety, read before operating your water heater

•

Immediately call your gas supplier from a neighbors
phone. Follow the gas supplier's instructions.

•

If you cannot
department.

reach your gas supplier,

call the fire

C. Use only your hand to turn the on/off control switch.
Never use tools. Follow these instructions
exactly. If
control switch is jammed, close the gas supply and call
Bosch Technical Support. Attempted
forceful repair
may result in a fire or explosion.
O. Do not use this appliance if any part has been under
water. Immediately call a qualified service technician to
inspect the appliance and to replace any part of the
control system and any gas control which has been
under water.

4.2

Power

• To start the appliance move the on/off switch to the
"on" position (I).
LCD will display the default temperature factory
setting 122°F (5O°C).
A. This appliance is equipped with electronic ignition for
lighting the main burners. When turning the heater on,
follow these instructions exactly.
B. Before operating the unit, set the On/Off switch to
the On (I) position.

WHAT TO DO IF YOU SMELL GAS
•

Do not try to light any appliance.

•

Do not touch any electric
phone in your building.

switch;

do not use any
Fi9. 29

6 720 608

108

Operation instructions

Off
•

To shut down the appliance
the "off" position (0),

4.3

Temperature

move the on/off switch to

selection

To select output water temperature:
•

Press buttons

and _7

in order to reach desired

temperature.

Fig. 30
If the outlet water temperature is set too high, the heater
can
produce
temperatures
that are too hot. A
temperature balance shower valve will automatically mix
in cold water to reduce such hot water temperature.
In
the event of any temperature fluctuation with the use of
a temperature
balance shower valve, refer to shower
valve manufacturer's
instructions for internal adjustment
setting. Adjustments
should be made to the hottest
setting in the shower valve. Additionally the temperature
control of the heater can be lowered to produce a more
comfortable
hot water temperature.

6 720 608

108

Operation instructions

Setting

the water

temperature

The desired temperature of the hot water can be adjusted on the front control panel of the heater.
The GWH-635-ES
has an electronically
controlled gas valve that modulates the burner input in response
varying hot water flow rates and/or changes in any incoming and outgoing water temperatures.
Note: selected temperature on heater's display will blink until that temperature has been reached.

to both

160

150;

140
C
r33
@

130

_OUTLET
TEM_ (50 degrees
122 degrees F)

Finlet-setat

•-_OUTLET
TEM_ (60 degrees
122 degrees F)

FinJet-setat

-'_-*OUTLET
TEM_ (75 degrees
122 degrees F)

FJnJet-setat

120
OUTLET TEMP, (85 degrees
122 degrees F)

F inlet - set at

110

100

90
1 gpm

2 gpm

3 gpm

4 gpm

Flow rate (gallons/minute)
Fig. 31

Row/temperature

5 gpm

6.4 gpm
6720607072-47.1

chart

Note: Low flowing fixtures are the leading cause of
temperature overshoot. To combat this symptom, clean
aerators and shower heads or replace with higher
flowing fixtures if necessary.

6 720 608

108

Operation instructions

4.4

Use of optional
accessory

remote

control

•

press reset button in order to return heater to normal
operation.

Fig. 35

Fig. 32

If the problem persists
contact your installer.

Remote contro/

The wireless
remote
control
accessory
and the
temperature selector buttons on the front of the water
heater operate identically.
Contact your installer or
distributor
to order the remote
control accessory.
Modification
of the water heaters interior control unit
(Fig. 48, component 25) is required when installing
remote control with this heater.

....

4.5
•

Reset button

the

4.7

Program

or error

code

will not reset,

button

The program button can be used on the appliance
on the remote control.

and

Programming
"Program"
function
Programming
actions are similar for both controls
(appliance control pad and wireless remote control).

NOTE: up to 6 remote controls can be
programmed
for one single water heater,
each with a range distance of 98 ft (30 m).

Operation

When a hot water tap is opened,
and LCD displays

indication

main burner ignites

_ .

Fig. 36

"Program"

•

Pressbuttons
memorized.

•

Hold "Program"

C_)

button

or _'
C_

to select temperatureto

button for 3 seconds

to save

temperature.
When LCD stops blinking, selected
been memorized.

Fi9. 33
•

LCD blinks until selected

temperature

maintain

the error symbol

Using "Program"
In order to select
•

Reset button

If the LCD displays

has

is reached.

If display blinks continously, heater cannot
or achieve selected temperature.

4.6

temperature

and error code

do not shut off power or unplug the heater.
Record the error code displayed on LCD and consult
"Troubleshooting" section (Section 6.8, page 36).

function
memorized

Press "Program"

temperature

key.

LCD shows pre-memorized
temperature,
the hot water selected temperature.

4.8

which is now

Locked condition

This condition is only valid for appliances utilizing one or
more remote controls,

.©
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