Bosch WR430-3K Installation Operation & Maintenance page 5

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 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.
For detailed requirements see:
• in Canada, CAN/CGA-B149 Installation Codes
• in U.S.A., ANSIZ223. 1 -latest edition, National Fuel Gas
Code.
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.
CLEARANCE
The WR430-3K is design certified for installation on a
combustible wall and for installation in an alcove or closet
with minimum clearances to combustible construction of 0
mm from back, 102 mm (4 inches) from sides, 305 mm (12
inches) from top and bottom, and 102 mm (4 inches) from
front. A minimum of 305 mm (12 inches) shall be allowed
for maintenance of serviceable parts. Clearance from vent
is dependent upon the clearance rating of the venting
material used; see venting page 6.
THIS APPLIANCE MUST BE INSTALLED IN ACCORDANCE WITH THE NATIONAL FUEL GAS CODE ANSI Z223. 1 -
latest edition in U.S.A. or CAN/CGA-B149 INSTALLATION CODES IN CANADA. LOCAL CODES AND/OR THE
REQUIREMENTS OF THE AUTHORITY HAVING JURISDICTION MUST BE FOLLOWED.
MOUNTING
The WR430-3K 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 x 4's
or 1/2" (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
Fig. 2 - Mounting the Heater
Expansion 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.
WALL STUDS
SUPPORT BOARD
1" X 4"
SPACE BOARD
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