– a) An unconfined space is one whose volume is greater than 50
cubic feet (1.42 cubic meter) per 1000 BTU/hr (292.81 Watts)
of the combined rating of all appliances installed in the space.
That would be 9950 cubic feet (281.8 cubic meters) for the
water heater alone.
– b) In unconfined spaces in buildings of conventional frame,
masonry, or metal construction, infiltration air is normally
adequate to provide air for combustion.
• Appliances located in confined spaces:
The confined space must be provided with two permanent openings,
one commencing within 12 inches (304.8mm) of the top and one
commencing within 12 inches (304.8mm) of the bottom of the
enclosure. Each opening must have a minimum free area of one
square inch per:
– 1000 BTU/hr (292.81 Watts) if all air is taken from inside the
– 2000 BTU/hr (585.62 Watts) if all air is taken from the outside by
– 4000 BTU/hr (1171.24 Watts)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 (304.8mm) of the ceiling of the enclosure.
This opening must have a minimum free area of one square inch per:
– 3000 BTU/hr (878.43 Watts) if all air is taken from the outside by
a direct opening or vertical duct.
Louvers, grills and screens have a blocking effect, when used, increase
the sizes of your openings by 300% for wood louvers (as wood type will
reduce the free air by 75%) and 43% for metal louvers (as metal will
reduce the free air by 30%). Refer to the National Fuel Gas Code for
complete information. In buildings of tight construction all air should be
taken from outside.
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:
▶ 1. Locate the heater where venting, gas and plumbing connections
are feasible and convenient.
▶ 2. The hot water lines should be kept short and insulated to save
energy. It is recommended to locate the water heater as close as
practical to the most frequently used hot water fixtures.
NOTICE: Risk of appliance freezing!
▶ The water in this water heater is cold and always
remains cold except for the times the burner is on. In
the event of power outage in conjunction with
freezing temperatures, it is recommended that the
heater be drained.
See chapter 7.2, page 41 "Winterizing" for draining
▶ 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.
Heater placement and clearances
The water heater design is approved for installation on a combustible
wall (see chapter 4.7 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. See fig. 6, page 10.
Hanging appliance on the wall
WARNING: Severe personal injury and property
Before mounting appliance:
▶ Check that there are no loose or damaged parts
inside the appliance.
▶ Confirm that the gas type of the heater matches the
gas supply you will be connecting the heater, see
Fig.2, page 8.
Front cover should be removed (see instructions on page
8) in order to inspect components visually.
▶ Do not install this appliance on a carpeted wall. The
heater must be mounted on a wall using appropriate
NOTICE: Risk of appliance freezing!
▶ In areas where outside temperature is routinely
below 32°F (0 °C) and the heater is to be installed on
the inside of an exterior wall, a minimum 2" air gap or
rigid insulation between the heater back and the wall
If wall is sheathed with plaster or drywall, it is recommended that two
support boards, either 1"x 4" or 1/2" (minimum) plywood first be
attached across a pair of studs, see fig. 31, page 28.
▶ Secure the wall mounting bracket provided with the heater to a wall
surface. The heater must be kept level on the wall surface, see fig.
32, page 28.
▶ Hang the appliance on the bracket, see fig. 33, page 29.
Installation instructions | 27
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