22
WARNING:
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings
exactly could result in serious injury,
death or property damage.
Never test for gas leaks with an open
fl ame. Use a commercially available
soap solution made specifi cally for the
detection of leaks to check all connec-
tions. A fi re or explosion may result
causing property damage, personal
injury or loss of life.
IMPORTANT NOTE: When pressure testing
gas supply lines at pressures greater than 1/2
psig (14 in. water column), the furnace must
be disconnected from the gas supply piping
system to prevent damage to the gas control
valve. If the test pressure is less than or equal
to 1/2 psig (14 in. water column), the furnace
must be isolated from the gas supply line by
closing the manual shut-off valve.
WARNING:
This furnace was equipped at the
factory for use with natural gas only.
A special kit, supplied by the manu-
facturer, is required to convert the
furnace to operate on LP/propane gas.
Failure to use the proper conversion
kit can cause fi re, explosion, property
damage, carbon monoxide poisoning,
personal injury, or death.
Figure 19. Typical Gas
Service Connection
MANIFOLD PRESSURE
ADJUSTMENT
Manifold pressures for low and high stages
are independently adjustable. Adjustment tap
locations on the valve are shown in Figure 20.
Manifold pressure would be adjusted below
procedure:
- Turn off gas shut off valve outside
furnace.
- Install manometer on the gas valve at the
outlet pressure tap.
- Turn on the shut off. Run furnace at high
fi re and set manifold pressure. Also set
manifold pressure while running at low
fi re (refer to Tables 6 and 7.)
- Ensure plug is tight after removing
manometer.
Conversion
Conversion of this furnace to use LP/propane gas
must be made by qualifi ed service personnel,
using
only
approved parts.
‡ = Insulation thickness greater than 3/8 inch, based on an R value of 3.5
(ft*°F*hr)/(BTU*in)
Table 4. Vent Protection
Some Utilities
Require Shut-
Off Valve to
be 4 to 5 feet
Above Floor
Denotes field-
provided and
installed
components.
Shut-Off Valve
with 1/8" NPT
Plugged Tap
Burner Viewport
Roll-Out Limit
Automatic Gas Valve
(with manual shut-off)
Burner
Assembly
Ground
Joint
Union
Dripleg
Upfl ow Models
Maximum Flue Pipe Length in
Unconditioned and Exterior Spaces
Winter Design
Temperature (
°F)
Without Insulation
(feet)
With Insulation
(feet)
‡
20
70
90
0
45
90
-20
35
80
