508107-01Issue 2041Page 46 of 58
4. Move gas valve switch to OFF.
5. Replace the access panel.
Failure To Operate
If the unit fails to operate, check the following:
1. Is the thermostat calling for heat?
2. Are access panels securely in place?
3. Is the main disconnect switch closed?
4. Is there a blown fuse or tripped breaker?
5. Is the lter dirty or plugged? Dirty or plugged lters will
cause the limit control to shut the unit o.
6. Is gas turned on at the meter?
7. Is the manual main shut-o valve open?
8. Is the internal manual shut-o valve open?
9. Is the unit ignition system in lockout? If the unit locks
out again, inspect the unit for blockages.
Heating System Service Checks
C.S.A. Certication
All units are C.S.A. design certied without modications.
Refer to the A93UH1E / 92G1UHE Operation and
Installation Instruction.
Gas Piping
If a exible gas connector is required or allowed by
the authority that has jurisdiction, black iron pipe shall
be installed at the gas valve and extend outside the
furnace cabinet. The exible connector can then be
added between the black iron pipe and the gas supply
line.
CAUTION
Do not over torque (800 in-lbs) or under torque (350
in-lbs) when attaching the gas piping to the gas valve.
WARNING
Gas supply piping should not allow more than 0.5” W.C.
drop in pressure between gas meter and unit. Supply gas
pipe must not be smaller than unit gas connection.
Compounds used on gas piping threaded joints should be
resistant to action of liqueed petroleum gases.
Testing Gas Piping
In case emergency shutdown is required, turn o the
main shut-o valve and disconnect the main power to
unit. These controls should be properly labeled by the
installer.
IMPORTANT
When pressure testing gas lines, the gas valve must be
disconnected and isolated. Gas valves can be damaged if
subjected to more than 0.5 psig (14” W.C.). See Figure 54.
Figure 54.
MANUAL MAIN SHUT-OFF
VALVE WILL NOT HOLD
NORMAL TEST PRESSURE
CAP
FURNACE
ISOLATE
GAS VALVE
1/8” N.P.T. PLUGGED TAP
When checking piping connections for gas leaks, use
preferred means. Kitchen detergents can cause harmful
corrosion on various metals used in gas piping. Use of a
specialty Gas Leak Detector is strongly recommended.
Do not use matches, candles, ame or any other source
of ignition to check for gas leaks.
WARNING
Testing Gas Supply Pressure
Gas Flow (Approximate)
Capacity
Seconds for One Revolution
Natural LP
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
Dial
-30 120 240 300 600
-45 80 160 200 400
-70 55 110 136 272
-90 41 82 102 204
-110 33 66 82 164
Natural-1000 btu/cu ft LP-2500 btu/cu ft
Table 15. Gas Meter Clocking Chart
To Next Page
Loading...
