Bosch WR400-1K Series Owner's manual

6 720 603 100 (03.05) AL
Instantaneous gas water heater
Models
WR400-1K…
· 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 wa-
ter heaters.
Suitable or heating potable water only. Not approved
or space heating purposes.
NOTICE TO INSTALLER: Please leave this manual with
the owner or affi adjacent to
appliance.
Note: In case o problems please contact your salesman or installer.
- Do not store or use gasoline or other lammable
vapors and liquids in the vicinity o this or any
other appliance.
- 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 rom a
neighbor’s phone. Follow the gas supplier’s
instructions.
- I you cannot reach your gas supplier, call the
ire department.
- Installation and service must be per ormed by a
quali ied installer, service agency or the gas
supplier.
ASTRAVAN DISTRIBUTORS, LTD.
123 Charles Street
North Vancouver, BC. V7H 1S1
Phone Canada: [phone]
Phone USA: [phone]
Web Site: www.astravan.com
READ INSTRUCTIONS CAREFULLY BEFORE INSTALLING
WARNING: I the in ormation in this manual is not
ollowed exactly, a ire or explosion may result
causing property damage, personal injury or death.

2
DIMENSIONS
Figure 1
Ma imum hydrostatic water pressure – 1.03 Mpa (150 p.s.i.)
Ma imum recommend working pressure – 0.69 Mpa (100 p.s.i.)
Minimum working pressure – 0.0138 Mpa (2 p.s.i.) at 2 Litres/min. (0.5 U.S. Gallons/min) free discharge
Minimum recommended inlet water pressure or use with showers 40 p.s.i.g.
Dimensions in Milimetres (inches)
* 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. – See page 8.
Model dimensions A B D E F
milimetres 460 755 130 diam. 740 542
inches 18 1/8 29 3/4 5 1/8 diam. 29 1/8 21 11/32
WR400 - 1
Size, mm Qt.
standard 34.28 kW 1.20 diam. 18
(0 - 2,000 Pieds) (117,000Btu/hr)
Propane/LP 0.79 diam. 18
high* 30.85 kW 1.20 diam. 18
(2,000 - 4,500 Pieds) ( 105,000Btu/hr)
Propane/LP 0.79 diam. 18
Main Burner Ori ices
WR400 Natural
WR400 Natural
Model Type o gas Altitude Input

3
FOREWORD
This design complies with CAN1-4.3-77 and ANS1Z21.10.3b
1994 as an instantaneous gas water heater. In addition the
unit complies with CAN1-2.17- M80 use at high altitude,
2.000- 4.500 feet above sea level.
Installation, operation and maintenance 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 heter is to operate is the same as specified
on the heater’s model/rating plate.
In addition of these instructions, 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 codes.
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 service of these water heaters.
LOCATION
Before installing the BOSCH instantaneous water heater
consideration must be given to proper location. The location
should be as close to a chimney or gas vent as practicable,
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 cannot be avoided, it is
recommended that a suitable drain pan, adequately
drained, be installed under the water heater. The
pan must no restrict combustion air flow.
AIR REQUIREMENTS
For safe operation, sufficient air combustion, ventilation and
dilution of the flue gas must be available. An insufficient
supply of air will result in a yellow luminous burner flame,
causing carboning or sooting of the heat e changer.
In order to prevent corrosion, make sure that the combustion
air is kept free of aggressive substances. Substances that
especially contribute to corrosion are halogenated
hydrocarbons (e.g., chlorine and fluorine) which are
contained in solvents, paint, adhesives, propellant gases,
various household cleaners, etc. Take precautionary
measures as necessary.
In unconfined spaces, in buildings of normal construction,
infiltration normally is adequate to provide air for combustion,
ventilation and dilution of the 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 on one square inch per 1,000
BTU/Hr* of total input rating of all the appliances in the
enclosure. One opening shall be within 12 inches of the top
and one within 12 inches of the bottom of the enclosure.
*Special Note
When the WR400-1 is installed in a confined space of
minimum size the openings described above must be
increased in to a size of 1 ½ square inches per 1,000 BTU/
Hr. In order words, when the WR400-1 is installed in a
minimum sized confined space the two openings that are to
be made in the enclosure within 12 inches of the top and
12 inches of the bottom must each have a minimum free
area of (1 ½ “) (117) = 175.5 square inches.

4
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 o 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 o
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.
For detailed requirements see:
•In Canada, CAN/CGA- B149 Installation Codes
•In U.S.A., ANSI Z223.1/NFPA 54, National Fuel Gas
Code.
WARNING!
1. Flammable materials gasoline, pressurized
containers, or any other items or articles that are
potentially ire hazards must never be placed on or
adjacent to the heater. The appliance area must be
kept ree o all combustible materials, gasoline and
other lammable vapors and liquids.
2. Do not obstruct the low o combustion and
ventilation air to the appliance.
CLEARANCE
The WR400-1 is design certified for installation on a
combustible wall and for installation in an alcove or closet
with minimum clearances to combustible construction of
0mm from back, 102mm (4 inches) from sides, 305mm (12
inches) from top and bottom, and 102mm (4 inches) from
front. 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; type B-1 vent is approved for 1 inch clearance, B-2
vent for 2 inch, etc.
MOUNTING
The WR400-1 is design certified for mounting to a wall.
The heater must not be installed on a carpeted wall. The
heater must be mounted to the wall using appropriate
anchoring materials.
Note: If wall is a stud wall sheathed with plasterboard it is
recommended that support board(s), either 1 4’s or ½ “
(minimum) plywood first be attached across a pair of studs
and then the heaters should be attached to the support
boards. See Figure 2.
Figure 2
E pansion and contraction of piping due to changing water
temperature in the pipes imparts movement to the heater
which, if mounted directly to a brittle, friable board, such as
plasterboard, can cause failure of mounting.
THIS APPLIANCE MUST BE INSTALLED IN ACCORDANCE WITH THE NATIONAL FUEL GAS CODE ANSI Z223.1/
NFPA 54 IN U.S.A OR CAN/CGA- B149 INSTALLATION CODES IN CANADA. LOCAL CODES AND/OR
REQUIREMENTS OF THE AUTHORITY HAVING JURISDICTION MUST BE FOLLOWED.
WALL STUDS
1”X4” SUPPORT BOARDS

5
DRIP TRAY
If the water heater is being mounted above a floor of
combustible construction the drip tray ( shipped loose in
the carton with the water heater) must be attached to the
bottom of the front cover of the water heater at the time of
installation. The drip tray should be attached to the front
cover, using screws provided, as shown in Figure 3.
Failure to use drip tray when installing unit above a floor of
combustible construction will cause an unsafe condition and
possible fire and will be in violation of A.G.A. and C.G.A
certification of the unit.
Figure 3
VENTING
The BOSCH instantaneous water heaters have built-in draft
diverters and are designed for indoor installation only. The
draft diverter outlet must be connected to a clear,
unobstracted vent of the same size, or larger, refer to:
•In Canada, CAN/CGA- B149 Installation Codes for
detailed requirements.
•In U.S.A., ANSI Z223.1/NFPA 54, National Fuel Gas
Code for detailed requirements.
The flue connection for the WR400-1 is 130 mm (5 inches);
however, in Canada for installations at high altitude (2,000-
4,500 ft. above sea level) a si inch (6”) flue is required.
For high altitude use the adaptor must be installed as shown
in Figure 4, without alteration, before connecting the si
inch flue to the unit. The adaptor must be secured to the
draft diverter outlet with a minimum of two screws.
Also, in Canada, the gas pressure regulator supplied with
the water heater is factory preset to deliver gas to the water
heater at the proper pressure setting for high altitude
operation, see PRESSURE REGULATION section of this
manual.
WARNING!
Failure to increase the vent size of the WR400-1 to si
inches and/or to assure that manifold pressure is set to proper
value listed on rating plate for applications at altitudes in
range of 2,000 to 4,500 ft. above sea level will cause unsafe
venting, asphy iation, and voids C.G.A. Certification.
WATER CONNECTIONS
The BOSCH instantaneous water heaters are provided with
two S- bend water connectors/adaptors that must be
connected to inlet and outlet connections on water valve
assembly, see Figure 1 and Figure 5, below.
Water valve and S-bends, top view
Figure 5
The purpose of the S- bend water connectors/ adaptors is
to provide threaded water connections that meet standards
used in North America, ANSI Standard Taper Pipe Thread
(1/2 “ NPT). The cold water supply should be connected to
S- bend attached to inlet of water valve and the hot water
connection should be made to S- bend attached to the outlet
of water valve.
If plastic piping is to be used, a 1.5 meter (appro . 5 feet)
length of metal piping must be attached to both the cold
water inlet and hot water outleet of the water heater.
Note: A shut-off valve should be placed in the cold water
supply line to the heater to facilitate servicing the
heater.
Figure 4
DRIP TRAY
5” 6” adaptor used
on high altitude model
WR 400 only