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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 switch on gas valve to OFF. Do not force.
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 circuit 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 lock out? If the unit locks
out again, call the service technician to inspect the unit
for blockages.
10. Is pressure switch closed? Obstructed flue will cause
unit to shut off at pressure switch. Check flue and
outlet for blockages.
11. Are flame rollout switches tripped? If flame rollout
switches are tripped, call the service technician for
inspection.
Heating Sequence of Operation
See Figure 34
1. When thermostat calls for heat, combustion air blower
starts.
2.
Combustion air pressure switch proves blower
operation. Switch is factory set and requires no
adjustment.
3.
After a 15 second pre-purge, the hot surface ignitor
energizes.
4.
After a 20 second ignitor warm-up period, the gas
valve solenoid opens. A 4 second trial for ignition
period begins.
5.
Gas is ignited, flame sensor proves the flame, and the
combustion process continues.
Page 26 of 36
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.
7.
To interrupt the 60 minute, move thermostat from
"Heat" to "OFF" then back to "Heat". Heating sequence
then restarts at step 1.
Gas Pressure Adjustment
Gas Flow (Approximate)
Gas Meter Clocking Chart
Capacity
1 cu ft
Dial
-045
80
-070
55
-090
41
-110
33
-135
27
Natural - 1000 btu/cu ft
Furnace should operate at least 5 minutes before checking
gas flow. Determine time in seconds for two revolutions of
gas through the meter. (Two revolutions assures a more
accurate time.) Divide by two and compare to time in Table
10. If manifold pressure matches Table 12 and rate is
incorrect, check gas orifices for proper size and restriction.
Remove temporary gas meter if installed.
NOTE: To obtain accurate reading, shut off all other gas
appliances connected to meter.
Supply Pressure Measurement
A threaded plug on the inlet side of the gas valve provides
access to the supply pressure tap. Remove the threaded
plug, install a field provided barbed fitting and connect a
manometer to measure supply pressure. See Table 12
for proper line pressure. Replace the threaded plug after
measurements have been taken.
Manifold Pressure Measurement
1. Remove the threaded plug from the outlet side of
the gas valve and install a field provided barbed
fitting. Connect to a manometer to measure manifold
pressure.
2.
Start unit and allow 5 minutes for unit to reach steady
state.
3.
While waiting for the unit to stabilize, observe the
flame. Flame should be stable and should not lift from
burner. Natural gas should burn blue.
Issue 2209
Seconds for One Revolution
Natural
2 cu ft
1 cu ft
Dial
Dial
160
200
110
136
82
102
66
82
54
68
LP - 2500 btu/cu ft
Table 10.
507330-03G / 31-5000662
LP
2 cu ft
Dial
400
272
204
164
136
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