Clearances: When facing the front of the room heater the minimum
clearances to combustible construction (material) are the following:
Right side 6 inches (152mm). Left side 6 inches (152mm).
Recommend 18 inches (457mm) on left side for servicing.
Do not install in alcove or closet. No horizontal projection above
heater permitted within 48 inches (122cm).
Ceiling 48 inches (122cm). Rear of draft hood 2 inches (51mm).
Open in front to provide service, access, and clearance to com-
bustibles.
Venting
1. Flue pipe must be as large as the flue collar on the draft diverter.
2. Maintain an upward slope of at least 1/4 inch (6mm) per foot
(.3m) of horizontal run.
3. Run flue pipe as directly as possible with a minimum of elbows.
4. Flue pipe should extend through the wall of a chimney to be
flush with inner wall.
5. Flue pipe must be adequately supported by metal strips.
6. Single wall vent pipe may be attached directly to the draft hood
of the room heater when a clearance of 2 1/2 inches (64mm)
is maintained between the single wall vent pipe and the com-
bustible wall of the room in which the room heater is located.
Use double wall vent pipe for a 1 inch (25mm) clearance to
combustibles.
7. For flue pipe running through walls and roof, use B-1 [1 inch
(25mm) clearance to combustibles) vent pipe.
8. Chimneys should extend at least 2 feet (.6m) above the roof
and above any object or nearby building within 10 feet (3m).
9. Open tees should not be used in the flue pipe.
10. Appliance must not be connected to a chimney flue that is
servicing a separate solid-fuel burning appliance.
For proper venting, do not attach a 90° elbow directly to draft di-
verter. If possible, attach 2 feet (.6m) of straight vent pipe before
an elbow is used. Use 45° elbows if possible.
Uninsulated single-wall metal pipe shall not be used outdoors
in cold climates for venting gas utilization equipment.
Ventilation and Combustion Air
Room heaters shall be installed in a location in which the facilities
for ventilation permit satisfactory combustion of gas and proper
venting under normal conditions. In buildings of conventional
frame, brick or stone construction without tight storm windows and
doors, infiltration is normally adequate to provide for combustion
and draft hood dilution.
Where appliances are installed in a confined space within a building,
the building being of unusually tight construction, air for combustion
and ventilation must be obtained directly from outdoors or from
such spaces that freely communicate with the outdoors. Under
these conditions, the confined space shall be provided with two
permanent openings, one near the top of the enclosure and one
near the bottom; each opening shall have a free area of not less
than one square inch (6.5cm
2
)per 1,000 BTU’s (.3KW/H) of total
input. The draft hood must be in the same atmospheric pressure
zone as the combustion air inlet to the appliance.
Liner and Insulated Liner
When you install a vented room heater into a masonry chimney
you must follow these steps.
1. The chimney must be lined and sized properly. Most masonry
chimneys are over sized and absorb too much heat to be con-
sidered a proper vent. If you have any doubts line the chimney
with the right size liner. If it’s unlined you must line it.
2. Use an insulated liner when the chimney is on the outside, three
sides exposed to the weather, and there is no clay liner in the
chimney. The insulation will help keep the flue gases warmer.
Insulated Vent Enclosure
Vented room heaters installed with the vent going directly to the
outside and above the eaves can cause poor venting. The cold
pipe will have a delay in proper venting and cause the room heater
to shut “off” by the vent safety switch. To prevent delayed venting
as well as condensation of flue products an insulated enclosure is
recommended.
Use type B 4" (102mm) diameter vent pipe and maintain at least a
one inch (25mm) clearance to combustibles.
Use metal thimble to protect vent pipe as it passes through com-
bustibles.
Figure 3
VENTING
CLEARANCES
38151-4-0320
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