506878-01
Page 48 of 62
Issue 1139
Gas Valve Operation
1.
STOP
! Read the safety information at the beginning of
this section.
2. Set the thermostat to the lowest setting.
3. Turn
OFF
all electrical power to the unit.
4. This furnace is equipped with an ignition device which
automatically lights the burners. Do
not
try to light the
burners by hand.
5. Remove the upper access panel.
6. Move gas valve switch to
OFF.
See Figure 57.
7. Wait five minutes to clear out any gas. If you then smell
gas,
STOP!
Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions. If you do not smell gas go to next step.
8. Move gas valve switch to
ON.
See Figure 57.
9. Replace the upper access panel.
10. Turn on all electrical power to the unit.
11. Set the thermostat to desired setting.
NOTE:
When unit is initially started, steps 1 through 11
may need to be repeated to purge air from gas line.
12. If the appliance will not operate, follow the instructions
“Turning Off Gas to Unit” and call your service technician
or gas supplier.
Turning Off Gas to Unit
1. Set the thermostat to the lowest setting.
2. Turn off all electrical power to the unit if service is to be
performed.
3. Remove the upper access panel.
4. Move gas valve switch to
OFF.
5. Replace the upper 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 filter dirty or plugged? Dirty or plugged filters will
cause the limit control to shut the unit off.
6. Is gas turned on at the meter?
7. Is the manual main shut–off valve open?
8. Is the internal manual shut–off valve open?
9. Is the unit ignition system in lockout? If the unit locks
out again, inspect the unit for blockages.
Heating Sequence Of Operation
1. When thermostat calls for heat, combustion air inducer
starts.
2. Combustion air pressure switch proves blower
operation. Switch is factory set and requires no
adjustment.
3. After a 15 second prepurge, the hot surface ignitor
energizes.
4. After a 20 second ignitor warm-up period, the gas valve
solenoid opens.
5. Gas is ignited, flame sensor proves the flame, and the
combustion process continues.
6. If flame is not detected after first ignition trial, the ignition
control will repeat steps 3 and 4 four more times before
locking out the gas valve. The ignition control will then
automatically repeat steps 1 through 6 after 60 minutes.
To interrupt the 60 minute period, move thermostat from
“Heat” to “OFF” then back to “Heat”. Heating sequence
then restarts at step 1.
Figure 57
Summary of Contents for 95G2UHV
Page 3: ...506878 01 Page 3 of 62 Issue 1139 EXPANDED VIEW Figure 1 ...
Page 28: ...506878 01 Page 28 of 62 Issue 1139 Figure 31 FIELD SUPPLIED WALL TERMINATION ...
Page 29: ...506878 01 Page 29 of 62 Issue 1139 Figure 32 ...
Page 35: ...506878 01 Page 35 of 62 Issue 1139 Figure 47 TRAP DRAIN ASSEMBLY USING 1 2 PVC or 3 4 PVC ...
Page 46: ...506878 01 Page 46 of 62 Issue 1139 TYPICAL WIRING DIAGRAM Figure 56 ...
Page 60: ...506878 01 Page 60 of 62 Issue 1139 Start Up Performance Check List UNIT SET UP ...
Page 61: ...506878 01 Page 61 of 62 Issue 1139 UNIT OPERATION Heating Mode Cooling Mode ...