Sterling RT - Manual (Page 22)

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Chart 6 - Troubleshooting
SYMPTOMS
A. Gas odor.
B. Delayed ignition.
C. Pilot will not light, or will not
stay
lit.
D. Main burners will not light.
POSSIBLE CAUSES
1. Shut off gas supply immedi-
ately.
2. Blocked heat exchanger.
3. Drafts around heater.
4. Negative pressure in the
building.
5. Blocked draft hood/fl ue
collector.
1. Excessive primary air.
2. Main burner ports clogged
near
pilot.
3. Pressure regulator set too low.
4. Pilot decreases in size when
main burners come on.
5. Pilot fl ame too small.
1. Main gas off.
2. Pilot adjustment screw turned
too low on combination main
gas valve.
3. Air in gas line.
4. Dirt in pilot orifi ce.
5. Extremely high or low gas
pressure.
6. Pilot valve not opening.
a. Faulty wiring.
b. Defective ignition control.
c. Defective valve.
7. No spark.
a. Faulty wiring.
b. Defective pilot.
c. Defective ignition control.
d. Sensor grounded.
1. Main gas off.
2. Lack of power at unit.
3. Thermostat not calling for heat.
4. Defective limit switch.
5. Improper thermostat or trans-
former wiring at gas valve.
6. Defective gas valve.
7. Defective thermostat.
CORRECTIVE ACTIONS
1. Inspect all gas piping and
repair.
2. Clean heat exchanger.
3. Eliminate Drafts. Refer to
installation.
4. See installation.
5. Clean draft hood/fl ue collector.
1. Close air shutter. Refer to
operation.
2. Clean main burner ports.
3. Reset manifold pressure.
Refer to operation.
4. Supply piping is inadequately
sized. Refer to installation.
5. Clean pilot orifi ce. Refer to
operation.
1. Open all manual gas valves.
2. Increase size of pilot fl ame.
3. Purge air from gas supply.
4. Remove pilot orifi ce. Clean
with compressed air or solvent.
(Do not ream).
5. Refer to operation.
6.
a. Inspect & correct all wiring.
b. Replace
c. Replace.
7.
a. Inspect & correct all wiring.
b. Replace.
c. Replace.
d. Inspect & correct ignition
system.
1. Open all manual gas valves.
2. Replace fuse or turn on power
supply.
3. Turn up thermostat.
4. Check limit switch with
continuity tester. If open,
replace limit switch.
5. Check wiring per diagrams.
6. Replace gas valve.
7. Check thermostat and replace
if
defective.