Bosch GWH 1600 PS User Manual

Index

Index

1Warning 2

2 Appliance details 3

2.1 GWH 1600 PS specifications
(Technical data) 3

2.2 Unpacking the GWH 1600 PS heater 4

2.3 General rules to follow for safe operation 4

2.4 Dimensions 5

3 Installation instructions 6

3.1 Introduction 6

3.2 Proper location for installing your heater 6

3.3 Heater placement and clearances 6

3.4 Mounting Heater 7

3.5 Combustion air requirements 8

3.6 Venting 9

3.7 Gas piping & connections 11

3.8 Measuring gas pressure 13

3.9 Water connections 13

3.10 Recirculation application 14

4 Operation instructions 14

4.1 For your safety read before operating
your water heater 14

4.2 Lighting instructions 15

4.3 To turn off appliance 15

4.4 Calibrating the thermostat 16

4.5 Winterizing 16

1 Warning

Warning: The heater must be isolated

from the gas supply piping system
during any pressure testing of that
system at test pressures equal to or
more than 0.5 psig.

Caution: Any changes or
modifications not expressly approved
by the party responsible for compliance
could void the user’s authority to
operate the equipment.

5 Maintenance and service 17

5.1 Maintenance intervals 17

5.2 Water valve 17

5.3 Pilot 18

5.4 Main burners 18

5.5 Vent assembly 18

5.6 Mineral scale build-up 18

6 Troubleshooting 20

6.1 Introduction 20

6.2 Pilot does not light 20

6.3 Pilot lights, but goes out when button released 20

6.4 Pilot goes out during or after hot water use 20

6.5 Burners do not light with water flow 21

6.6 Hot water temperature fluctuates at tap 21

6.7 Water is too hot 21

6.8 Water is not hot enough 22

6.9 Burners ignite without hot water flow 22

6.10 Low hot water pressure 22

6.11 Noise when heater is running 22

6.12 Burners do not operate cleanly;
yellow flames when operating 22

7 Protecting the environment 23

8 Interior components and diagram parts list 24

8.1 Interior components 24

8.2 Components diagram 25

8.3 Parts list 26

Fig. 1

9 Twelve Year Limited Warranty 27

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2 Appliance details

Appliance details

2.1 GWH 1600 PS specifications
(Technical data)

Approved in US/Canada

Capacity

GWH 1600 PS: 4.3 GPM

Maximum output

GWH 1600 PS: 96,600 Btu/hr

Maximum input

GWH 1600 PS: 117,000 Btu/hr

Efficiency in %

Recovery efficiency 80%

Min. Output

GWH 1600 PS: 23,400 Btu/hr

Gas Requirement

Gas connection (inches) - ½” NPT

Inlet gas pressure under maximum operation*

• Propane: 10.5” - 14” water column

• Natural Gas: 5.7” - 14” water column.

* To measure Gas Pressure, see Measuring Gas
Pressure, chapter 3.8.

Dimensions

• Depth (in): 8 ¾” (222 mm)

• Width (in): 18 ¼” (463 mm)

• Height (in): 29 ¾” (756 mm)

• Weight: 44 lb (20 kg).

Gas types

Natural Gas.
LP Gas

Safety devices

• Flame failure device (ionization thermocouple)

• Pressure relief valve (supplied with heater)

• Over heat prevention (temperature limiter).

Venting

• Natural Draft

• Vent diameter (inches) - 5”

• Minimum height (feet) - 6’ with no elbows

• Vertical termination

• Sidewall termination only with AQ1 power vent kit.

Water

• Hot water connection (inches) - ½” NPT

• Cold water connection (inches) - ½” NPT

• Water valve material: Brass

• Minimum water flow: 0.5 gallon/minute (1.9 l/m)

• Minimum recommended water pressure: 30 PSI

(2.07 bar)

• Connections:

– Bottom of heater

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3

Appliance details

2.2 Unpacking the GWH 1600 PS
heater

This heater is packed securely.

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 is
located on the right side panel of the cover.

Fig. 2 Rating plate sticker

A Serial number
B Type of gas

The box includes:

• Pressure relief valve

•Mounting screws

• Product registration card

• Installation manual (additional copies can be

downloaded at www.boschwaterheating.com)

• Incandescent particle tray.

Please complete and return the enclosed product
registration card.

The GWH 1600 PS is not approved or designed
for:

• Manufactured (mobile) homes, RV's, boats or any

mobile installation

• Heating or other recirculating/pumping applications*

• Installation in a bathroom, bedroom or any other

habitable room normally kept closed.

* 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 3.10.

In Canada: The Installation must conform with CGA
B149.(1,2) INSTALLATION CODES and /or local
installation codes.

• 2. You must vent your heater. See section on
VENTING.

• 3. Carefully plan where you install the heater. Correct
combustion air supply and vent pipe installation are
very important. If not installed correctly, fatal
accidents can be caused by lack of air, carbon
monoxide poisoning or fire.

• 4. 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 ½ Psig
(3.5 kPa).

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

• 6. 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 and 3.8 to verify proper gas line
sizing.

• 7. 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.

• 8. 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.

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

• 10. 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 4.5 on Winterizing.

• 11. 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.

2.3 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.

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2.4 Dimensions

Appliance details

Fig. 3 Dimensions in Inches and (mm)

4 Heat exchanger
5 Burner
11 Water valve
20 Gas connection
36 Front cover
37 Holes for hanging on wall
38 Exhaust pipe union
39 Draft diverter
40 Gas valve
49 Observation window
50 Piezo Igniter button
51 Off button
52 Pilot button
53 On button

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Installation instructions

3 Installation instructions

3.1 Introduction

Please follow these instructions. Failure to follow
instructions may result in:

B Damage or injury.
B Improper operation.
B Loss of warranty.

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 for installing your
heater

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:

B 1. Locate the heater where venting, gas and

plumbing connections are feasible and convenient.

B 2. The hot water lines should be kept short to save

energy. Centrally locating the water heater is best. It
is always best to have hot water lines insulated.

Warning: The heater must be isolated
from the gas supply piping system
during any pressure testing of that
system at test pressures equal to or
more than 0.5 psig.

Warning: Place the heater in a location
where water leaks will do NO DAMAGE
to adjacent areas.

3.3 Heater placement and clearances

The GWH 1600 PS 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
non-combustible materials listed below. See also Fig. 4.

A. Top 12 inches (306 mm)
B. Front 4 inches (100 mm)
C. Back 0 inches
D. Sides 4 inches (100 mm)
E. Bottom 12 inches (306 mm)

B 3. Do not install in a bathroom, bedroom or any other

habitable room normally kept closed.

Warning: The water in this water
heater is cold and always remains cold
except for the times that hot water is
being used. DO NOT INSTALL IN AN
AREA WHERE IT COULD FREEZE.
Drain the heater entirely if freezing
temperatures are anticipated in area
where heater is installed. See chapter

4.5 for draining instructions.
To prevent any freeze damage,
introduce short bursts of compressed
air (20-40psi) through these
connections to remove the residual
water in the horizontal pipes and water
valve.

Warning: Flammable materials,
gasoline, pressurized containers, or any
other items or articles that are potential
fire hazards must NOT be placed on or
adjacent to the heater. The appliance
area must be kept free of all
combustible materials, gasoline and
other flammable vapors and liquids.

TOP (A)

FRONT (B)

BACK

SIDES

BOTTOM (C)

Fig. 4 Minimum clearances

Model GWH 1600

12 inches (306 mm)

4 inches (100 mm)

0 inches

4 inches (100 mm)

12 inches (306 mm)

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3.4 Mounting Heater

Warning: before starting installation:

B check that there are no loose parts

inside the appliance

B ensure that gas pipe, gas valve, and

burner have no damage and are
properly fitted.

B Read chapter 2.2 to verify proper gas

type and to check all parts are included
in box.

Front cover should be removed in order to
inspect components visually (see

i

instructions below).

Remove cover and inspect.

B Loosen the fixing screw, bottom of the front cover.
B Remove the outer cover by pulling it forwards and

then lifting upwards, see Fig. 6.

B Ensure that the flue terminal is clear.
B After inspection, replace front cover.

Installation instructions

Fig. 6 Remove front cover

Install incandescent particle tray.

B Install incandescent particle tray using screws

provided as shown in Fig. 5.

Screws

Incandescent particle tray

Fig. 5 Incandescent particle tray illustration

Mounting heater.

Warning:

B Do not install this appliance on a

carpeted wall.

The heater must be mounted on a wall using
appropriate anchoring materials. If wall is sheathed with
plasterboard, it is recommended that support board(s),
either 1x4’s or 1/2" (minimum) plywood first be
attached across a pair of studs and then the heater
should be attached to the support boards, see Fig. 7.

Fig. 7 Support board

B Secure the two included L shaped hooks to wall

studs or support board 13 1/4” apart. (See Fig. 7).

B Hang heater on two L shaped hooks. (See Fig. 8).

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Fig. 8 Secure heater to wall

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Installation instructions

3.5 Combustion air requirements

The AquaStar 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 down through
the unit's vent pipe is capable of freezing these
components. This installation manual specifies the
minimum vertical vent pipe height 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 all the combustion appliances in
the building are not being supplied with a sufficient
amount of make-up air. A wood stove or furnace can pull
cold air down the Aquastar's vent pipe, freezing the cold
water in the heat exchanger or water valve causing
damage. Supplying more combustion air for all
combustion appliances is the solution. A HVAC
specialist should be consulted to design solutions for
providing more make-up air if necessary. Observe the
following guidelines concerning combustion air.

Appliances located in unconfined spaces:
a) An unconfined space is one whose volume is greater

than 50 cubic feet per 1000 Btu per hour of the
combined rating of all appliances installed in the space.
That would be 5850 cubic feet for the AquaStar GWH
1600 PS alone.

b) 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
Fuel Gas Code. Consult a HVAC specialist if your air
infiltration rate is questionable.

Appliances located in confined spaces:

The confined space must be provided with 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 by

horizontal ducts.

• 4000 Btu/hr if all air is taken from the outside by

direct openings or vertical ducts.

Or the confined 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 by a

direct opening or vertical duct.

Louvers, grills and screens have a blocking effect. If the
effective free area is not known, increase the sizes of
your openings by 400% if your louvers are wood and by
135% if your louvers are metal. Refer to the National
Fuel Gas Code for complete information. In buildings of
tight construction all air should be taken from outside.

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Installation instructions

3.6 Venting

Danger: Do not reduce the vent pipe

size. Do not put an elbow directly on top
of heater. Failure to follow venting
requirements may cause deadly exhaust
gases to enter living space.

B Minimum vent pipe diameter: 5 inches
B Minimum vertical vent height: 6 feet, with no elbows
B Establish 12 inch rise before any elbow

The heater must be vented to the outside following all
local ordinances and specifications for installing a gas
appliance vent or chimney. The heater must be located
as close as practicable to a vertically rising chimney or
vent that has a listed vent cap at its termination point.
The venting system must be designed and constructed
so as to develop a positive flow adequate to remove flue
gasses to the outdoors. Consult the National Fuel Gas
Code if the vent will have elbows or share venting with
another natural draft appliance.

Warning: Do not combination vent with
a mechanically vented appliance.

B All gas vent sections must be secured to each other

with sheet metal screws and be properly supported.

Horizontal runs:

Any gas vent section that is greater than 45 degrees
from the vertical is considered horizontal. Horizontal
sections must slope upwards at least ¼ inch for every
foot of its horizontal length and be properly supported.
Keep the horizontal section short and avoid too many
elbows. The maximum horizontal run allowed is half of
the total vertical vent height; horizontal vent connectors
and elbows are not to be considered in the total gas
vent height.

Vent termination:

The gas vent constructed of double wall Type B gas
vent must terminate above the roof surface with a listed
vent cap at a height that's in accordance with Fig. 11
and table 2, provided they are at least 10 feet (2.4 m)
from a vertical wall or similar obstruction. All other gas
vents that are not able to terminate within the minimum
specified height allowed must terminate not less than 2
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).

3.6.1 Horizontal venting

Warning: Horizontally venting to a

vertically constructed vent stack along
an outside wall of a building is not
permissible.

Warning: Horizontally venting to a
sidewall vent terminator (without power
vent) is not permissible.

A power vent (model AQ1), with a proof-of-draft safety
interlock device, is required and is available for sidewall
venting. Contact your dealer. In the Commonwealth of
Massachusetts power vented applications must utilize
proof-of-draft safety interlock device.

3.6.2 Vertical venting

B A 5 inch diameter gas vent constructed of double

wall Type B gas vent is required. A 6 inch vent is
required in elevations greater than 2000 feet, see
Fig. 10. Under no circumstances should the vent
pipe be reduced in size.

B An approved gas vent connector must be attached

to the top of the water heater and rise vertically at
least 12" before entering into an approved gas vent
connector elbow.

B The minimum vertical gas vent height allowed is 6

feet; horizontal vent connectors and elbows are not
to be considered in the total gas vent height.

Fig. 9 Flat roof

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Fig. 10 Vent Adaptor for High Altitude Installations

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