Bosch Appliances W 125-T1, W125K User Manual

Instantaneous gas water heater

Models

W 125...T1

• installation

• operation

• maintenance

The Bosch instantaneous water heater is a high efficiency,
space saving answer to your water heating needs. All
Bosch instantaneous water heaters heat water only as
required; no energy is lost maintaining a large volume of
water at elevated temperatures as in tank-type storage
water heaters.
Suitable for heating potable water only – not approved
for space heating purposes.

READ INSTRUCTIONS CAREFULLY BEFORE INSTALLING

NOTICE TO INSTALLER: Please leave this

manual with the owner or affix adjacent to
appliance.

ASTRAVAN DISTRIBUTORS, LTD.

6 720 606 447 CA (05.05) AL

123 Charles Street
North Vancouver, B.C. V7H 1S1
Phone Canada: [phone]
Phone USA: [phone]
Web Site: www.astravan.com

WARNING: If the information in this
manual is not followed exactly, a fire or
explosion may result causing property
damage, personal injury or death.

- Do not store or use gasoline or other flamma­ble vapors and liquids in the vicinity of this or
any other applicance.

- WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not

use any 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.

Note: In case of problems please contact your salesman or installer

DIMENSIONS

Figure 1

Maximum hydrostatic water pressure - 0.97 MPa (150 p.s.i.)
Maximum recommended working pressure - 0.69 MPa (100 p.s.i.)
Minimum working pressure - 0.01 1 MPa (2 p.s.i.) at 1.6 Litres/min. (0.5 U.S. Gal/min.) free discharge
Minimum recommended inlet water pressure for use with showers 40 p.s.i.g.

NG

Tap pressure inch
Manifold burner pressure inch

Dimensions in millimetres (inches)

ABCDEFGH I J

270 610 230 190 70 562 350 312 102 138

(10 5/8) (25 3/8) (9 1/8) (7 1/2) (2 3/4) (22 1/8) (13 3/4) (12 1/4) (4) (5 3/8)

Model Type of Gas Altitude Input

W 125 K…

W 125 K…

natural standart 11.7 kW 1.25 diam. 6

propane (0-2,000 ft.) (40,000 Btu/hr) 0.76 diam. 6

natural high * 10.5 kW 1.25 diam. 6

propane (2,000-4,500 ft.) (36,000 Btu/hr) 0.76 diam. 6

Altitude

Standard High Standard High

5,7 4,6 10,5 8,4

3,35 2,7 10,2 8,1

Tap pressure inch
Manifold burner pressure inch

LPG

Main Burner Orifices

Size, mm Qt.

Altitude

* The high altitude ratings listed are Canadian Gas Association high altitude ratings and are only valid in Canada.
In the U.S., the National Fuel Gas Code, ANSI Z223.1/NFPA 54 recommends for high altitude installations above
2,000 feet, that the input rate be reduced 4% for each 1,000 feet above sea level.

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FORWARD

This design complies with CAN 1-4.3-77 and ANS1
Z21.10.3b 1994 as an instantaneous gas water heater. In
addition the unit complies with CAN1-2.17-M80 for use at
high altitude, 2.000-4.5000 feet above sea level.

Instalation, operation and maitenance information is provided
in this manual. Installation and operation instructions should
be thoroughly reviewed before proceeding with installation
of the BOSCH instantaneous gas water heater.

The BOSCH instantaneous gas water heater is designed to
operate on natural or propane gas; however, make sure that
gas on which heater is to operate is the same as specified
on the heater’s model/rating plate.

In addition to these instrutions,the water heater shall be
installed in accordance with CAN1-B149 Installation Code
(in Canada) or ANSI Z223-1/NFFA 54 National Fuel Gas
Code (in U.S.) and/ or local installation cades. These shall
be carefully followed in all cases.

INSTALLATION INSTRUCTIONS

Note: Proper plumbing, venting, gas connections and an

adequate supply of combustion air are required for
safe and reliable operation. Ability equivalent to that
of a licensed tradesman in the field involved is required
for installation and/or servicing of these water heaters.

LOCATION

Before installing the BOSCH instantaneous gas water
heater consideration must be given to proper location. The
BOSCH W125K... instantaneous gas water heater may be
installed to supply hot water to remote locations. Location
should be as close to a chimney or gas vent as practical, in
an area with an adequate air supply and as centralized with
the piping system as possible. The heater should not be
located in an area where it will be subject to freezing. The
heater should be located in an area where leakage of the
heater or its connections will not result in damage to the
area adjacent to the heater or to lower floors of the structure.

Note: When such locations can not be avoided, it is

recommended that a suitable drain pan, adequately
drained, be installed under the heater. The pan must
not restrict combustion air flow.

AIR REQUIREMENTS

For safe operation, sufficient air for combustion, ventilation
and dilution of flue gases must be available. An insufficient
supply of air will result in a yellow luminous burner flame,
causing carboning or sooting of the heat exchanger.

In unconfined spaces, in buildings of normal construction,
infiltration normally is adequate to provide air for combustion,
ventilation and dilution of flue gases. However, a confined
space must be provided with two permanent openings to
provide combustion and ventilation air to the appliance. Each
opening shall have a free area of on square inch per 1,000
Btu/hr of total input rating of all the appliances in the
enclosure, but not less than 100 square inches. One opening
shall be within 12 inches of the top and one within 12 inches
of the bottom of the enclosure.

For either a confined or unconfined space in a building of
tight construction, with inadequate infiltration, air must be
drawn from the outdoors or from spaces that freely
communicate with the outdoors. Two permanent openings
located as indicated above are to be provided as follows:

1. When communicating with outdoors directly, or by
means of vertical ducts, each opening shall have a free
area of not less than one square inch per 4,000 Btu/hr of
total input of all appliances in the space.

2. When communicating with outdoors by means of
horizontal ducts, each opening shall have a free area
of not less than one square inch per 2,000 Btu/hr of total
input of all appliances in the space.

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WARNING

1. Flammable materials, gasoline, pressurized containers,
or any other items or articles that are potentially fire
hazards must never 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.

2. Do not obstruct the flow of combustion and ventilation
air to the appliance.

CLEARANCES

This heather is designed certified for installation on a
combustible wall, in an alcove with minimum clearances to
combustible construction of 51mm (2 inches) from sides,
305mm (12 inches) from top and bottom. A minimum of
305mm (12 inches) shall be allowed for maintenance of
serviceable parts. Clearance from vent is dependent upon
the clearance rating of the venting material used; that is
type B-1 vent is approved for 1 inch clearance, B-2 vent for
2 inch, etc.

MOUNTING

The W125K…is designed certified for mounting to a wall.
The heather must not be installed directly on a carpeted
wall.

The heather must be mounted to the wall using appropriate
anchoring materials, through the four holes provided.

Expansion and contraction of piping due to changing water
temperature in pipes imparts movement to heater which, if
mounted directly to a brittle, board such as plasterboard
can cause failure of mounting.

Heater must be mounted level to assure proper operation.

VENTING

The BOSCH model W125K… instantaneous gas water
heater has a built-in a draft diverter is designed for indoor
installation only. The draft diverter outlet must be connected
to a clear, unobstructed vent of the same size or larger, refer
to:

- In Canada, CAN 1-B149 Installation Code for detailed

requirements

- In U.S., ANZI Z223.I/NFPA 54 National Fuel Gas Code

for detailed requirements

- The minimum length of a vertical vent up to the terminal

must be 2 ½ feet.

WATER CONNECTIONS

G772_179

Figure 2

RELIEF VALVE

The listed pressure relief valve supplied must be installed
near the hot water outlet at time of installation of the
heater. No valve is to be placed between the relief valve
and the heater. A drain line must be connected to the
relief valve to direct discharge to a safe location. Do not
install reducing coupling or any other restriction in the
discharge line. The discharge line must be installed so
as to allow complete
drainage of both the valve and the line.

GAS CONNECTIONS

Before connecting the gas supply to the heater check
heater’s model/rating plate to make sure that gas on which
heater is to operate is the same as specified on the model/
rating plate.

The W125K…instantaneous gas water heater is supplied
with a gas pipe, a gas pressure regulator and a manual gas
cock that must be installed on the heater before attaching
the gas supply line, see figure 3. Failure to install gas pipe,
the main manual gas valve and the pressure regulator, or
the failure to install them in the sequence show in figure 3
will be in violation of the A.G.A. and C.G.A. certification of
the unit and can cause damage to heat changer.

BOSCH water heaters are shipped from the factory with
the gas pressure regulators preset for the gas shown on the
rating plate to the correct pressure.

- In Canada, for high altitude operation;

- In U.S., for standard altitude operation unless specially
marked as a high altitude unit.

The W125K comes supplied with a ½’’ NPT cold water inlet
adapter and a flexible wire braid hot water outlet with a ½’’
NPT connection.

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