Sears N8MPL075B12B1 Furnace User Manual


 
Ventdampersonanyapplianceconnectedto the common vent
can cause condensation and corrosion in the venting system. Do
not use vent dampers on appliances common vented with this fur-
nace.
8. Gas Supply and Piping
CARBON MONOXIDE POISONING, FIRE AND
EXPLOSION HAZARD.
Gas Piping Requirements
NOTE: The gas supply line must be installed by a qualifted service
technician in accordance with all building codes.
NOTE: In the state of Massachusetts.
Failure to follow safety warnings exactly could
result in serious injury, death, and/or property
damage.
Models designated for Natural Gas are to be used
with Natural Gas ONLY, unless properly converted to
use with LP gas.
Gas SupplyRequirements
1.
Use only the Type of gas approved for this furnace. See rating
plate for approved gas type. 2.
Gas input must not exceed the rated input shown on the rating
plate. Overfiring will result in failure of heat exchanger and
cause dangerous operation.
Do not allow minimum supply pressure to vary downward. Do-
ing so will decrease input to furnace. Refer to Table 3 for gas
supply. Refer to Table 6 and Table 7 for manifold pressures.
I Gas Pressures
Supply Pressure
Gas Type
Recommended Max.
Natural 7" 14"
Propa ne 11" 14"
Min,
4.5"
11"
a. Gas supply connections MUST be performed by a li-
censed plumber or gas fitter).
b. When flexible connectors are used, the maximum length
shall not exceed 36" (915 mm).
c. When lever handle type manual equipment shutoff
valves are used, they shall be T-handle valves.
d. The use ofcopper tubing for gas piping is NOT approved.
Install gas piping in accordance with local codes, or in the ab-
sence of local codes, the applicable national codes.
It is recommended that a manual equipment shutoff valve be
installed in the gas supply line outside the furnace. Locate
valve as close to the furnace as possible where itis readily ac-
cessible. Refer to Figure 12.
FIRE HAZARD
Failure to follow safety warnings exactly could
result in death or personal injury.
Use wrench to hold furnace gas control valve when
turning elbows and gas line to prevent damage to
the gas control valve and furnace.
Typical Gas Piping (N8MP)
Drip Leg and Union, Union* should be outside the
cabinet. Manual shut- off valve MUST be upstream of
dripleg, union, and furnace.
Use elbows and3"pipenippletoconnectvalveto
pipingwhen using right sidegas pipeentry. _.
LPLowpressure 3'_pipe
switch.
Manual shut- off
valve
Alterative
25-24-86
* Union may be installed inside the cabinet when necessary because of clearances.
3. Useblackironorsteelpipeandfittingsorotherpipeapproved 4. Use pipe thread compound which is resistant to natural and
by local code. LP gases.
_] 44101 261302