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SECTION 4: CLEARANCES TO COMBUSTIBLES
7 of 51
SECTION 4: CLEARANCES TO COMBUSTIBLES
4.1 Required Clearances To Combustibles
Clearances are the required distances that
combustible objects must be away from the heater
to prevent serious fire hazards. Combustibles are
materials that catch on fire and include common
items such as wood, paper, rubber, fabric, etc.
Maintain clearances to combustibles at all times for
safety.
Clearances for all heater models are located on the
serial plate of the heater and throughout the manual.
Check the clearances on the serial plate to make
sure the product is suitable for your application and
the clearances are maintained. Read and follow the
safety guidelines below:
• Keep gasoline or other combustible material
including flammable objects, liquids, dust or
vapors away from this heater or any other
appliance.
• The stated clearances to combustibles
represents a surface temperature of 90° F (50°
C) above room temperature. Building materials
with a low heat tolerance (such as plastics, vinyl
siding, canvas, tri-ply, etc) may be subject to
degradation at lower temperatures. It is the
installer’s responsibility to assure that adjacent
materials are protected from degradation.
• Consult local Fire Marshal, Fire Insurance Carrier
or other authorities for approval of proposed
installation when there is a possibility of
exposure to combustible airborne materials or
vapors.
4.2 Clearances To Combustibles
Clearances must be as indicated on Page 7, Figure
4. If clearances to combustibles are not indicated,
then installation clearances apply.
Figure 4: Installation Clearances and Clearances to Combustibles
WARNING
Fire Hazard
Keep all flammable objects, liquids and
vapors the required clearances to
combustibles away from heater.
Some objects can catch fire or explode
when placed close to heater.
Failure to follow these instructions can
result in death, injury or property damage.
6"
(15 cm)
31"**
(79 cm)
3"
(8 cm)
6"
(15 cm)
Clearances to Combustibles
24" for
adequate
air flow access
axial fan.
10'
(3 m)
Wall
Terminal
Roof Terminal
Top
20' (6.0 m) - 30' (9.1 m)
Max. Mounting Height*
Installation Clearances
(Optional separated
combustion concentric
venting shown.)
* Recommended mounting height varies with heater input.
Heaters may be mounted at a higher level if destratification
fans are installed.
Note: Venting directly from top of heater not applicable
on Models 150 - 400.
Clearance to Vent: 2" (5 cm)
**31" (79 cm) minimum is necessary
for servicing.
The heater must always be installed at least 6' (2 m) above the floor.
The vent pipe must have clearance from combustibles by 2" (5 cm).
If installed at low levels where individuals can come in contact with hot heat
exchanger components, adequate guarding must be provided.