Troubleshooting
WARNING: Turn off heater and let cool before ser- vicing. Only a qualified service person should service and repair heater.
CAUTION: Never use a wire, needle, or similar object
to clean pilot. This can damage pilot unit.
Note: All troubleshooting items are listed in order of operation.
The two most common causes of a malfunctioning gas appliance are:
1. Loose wiring connections
2. Construction debris clogging the pilot and/or gas control valve filter
OBSERVED PROBLEM | POSSIBLE CAUSE | REMEDY | ||
Ignitor will not spark or pilot will not light | 1. | No gas supply, or shutoff valve is OFF | 1. | Check to see if you have gas supply and |
| 2. | Air in gas line | 2. | that equipment shutoff valve is opened |
| Repeat lighting procedure several times | |||
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| to purge all air out of lines. If after re- |
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| peated attempts appliance does not light, |
| 3. | Construction debris clogging pilot orifice | 3. | call for qualified service and repair. |
| Remove debris and dirt, inspect and | |||
| 4. | Low gas pressure | 4. | clean any other possible obstructions |
| Contact your gas supplier to check | |||
| 5. | Kinked pilot line | 5. | pressure |
| Have a qualified technician replace pilot | |||
| 6. | Control valve knob is not opening | 6. | line |
| Replace control valve (Refer to Replace- | |||
| 7. | No power to unit or the ignition module | 7. | ment Parts, page 28) |
| Check that main power is on and that | |||
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| or power transformer is bad |
| all wire connections are made correctly |
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| to the ignition model (see Wiring Dia- |
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| gram, page 22). Check for 24 VAC at the |
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| secondary side of the transformer. If 24 |
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| VAC is present, and the module does not |
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| operate, have the module replaced oth- |
| 8. | Vent damper not fully open | 8. | erwise have the transformer replaced. |
| Open vent damper until fully locked in | |||
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| OPEN position |
Pilot will not stay lit | 1. | Loose wiring on ignitor wire to ignition | 1. | Check wiring connection. Refer to Wir- |
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| module and/or poor ground to ignition |
| ing Diagram, page 22, and/or check |
| 2. | module | 2. | ground wire to ignition module |
| Pilot flame too low to sense | Clean and adjust pilot burner and check | ||
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| gas supply and inlet pressure to unit |
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| Note: Have a qualified technician replace |
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| pilot assembly if broken or corroded |
No gas to burner, although wall switch and | 1. | Wall switch wires defective or too long | 1. | Check electrical connections |
valve are set to the ON position |
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Frequent pilot outage | 1. | Pilot flame may be too low, causing | 1. | Clean and adjust pilot flame for maximum |
| 2. | safety pilot to “drop out” | 2. | flame impingement on thermopile |
| Improper venting or excessive blockage | Have the vent system inspected, includ- | ||
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| ing the termination cap. Remove any |
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| restriction or obstruction |
26 | www.desatech.com |