Table 8ÐTroubleshootingÐCooling and Heating
SYMPTOM | CAUSE | REMEDY | |
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| Power Failure | Call power company | |
| Loss of Charge | Evaluate unit for possible refrigerant leak | |
| Switch open | ||
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| Fuse blown or circuit breaker tripped | Replace fuse or reset circuit breaker | |
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Compressor and outdoor fan will not start. | Defective thermostat, contractor, transformer, or | Replace component | |
control relay | |||
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| Insufficient line voltage | Determine cause and correct | |
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| Incorrect or faulty wiring | Check wiring diagram and rewire correctly | |
| Thermostat setting too high | Lower thermostat setting below room tempera- | |
| ture | ||
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| Faulty wiring or loose connections in compressor | Check wiring and repair or replace | |
| circuit | ||
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| Compressor motor burned out, seized, or internal | Determine cause | |
Compressor will not start but outdoor fan | overload open | Replace compressor | |
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Defective run/start capacitor, overload, start relay | Determine cause and replace | ||
runs. | |||
One leg of | Replace fuse or reset circuit breaker | ||
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| Determine cause | ||
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| Low input voltage | Determine cause and correct | |
| (20 percent low) | ||
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| Refrigerant overcharge or undercharge | Recover refrigerant, evacuate system, and re- | |
| charge to capacities shown on nameplate | ||
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| Loss of Charge | Evaluate unit for possible refrigerant leak | |
| Switch open | ||
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| Defective compressor | Replace and determine cause | |
Compressor cycles | Insufficient line voltage | Determine cause and correct | |
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(other than normally satisfying thermostat). | Blocked outdoor coil (cooling) | Determine cause and correct | |
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| Defective run/start capacitor, overload or start | Determine cause and replace | |
| relay | ||
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| Defective thermostat | Replace thermostat | |
| Faulty | Replace | |
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| Restriction in refrigerant system | Locate restriction and remove | |
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| Dirty air filter | Replace filter | |
| Unit undersized for load | Decrease load or increase unit size | |
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| Thermostat set too low | Reset thermostat | |
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| Low refrigerant charge | Locate leak, repair, and recharge | |
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Compressor operates continuously. | Leaking valves in compressor | Replace compressor | |
| Frosted outdoor coil with incorrect | Check defrost time settings. Reset as necessary. | |
| defrost operation (heating) | Check defrost temperature switch. Replace as necessary. | |
| Air in refrigerant system | Recover refrigerant, evacuate system, and re- | |
| charge | ||
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| outdoor coil dirty or restricted | Clean coil or remove restriction | |
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| Dirty air filter | Replace filter | |
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| Dirty outdoor coil | Clean coil | |
Excessive head pressure. | Refrigerant overcharged | Recover excess refrigerant | |
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Air in refrigerant system | Recover refrigerant, evacuate system, and re- | ||
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| charge | ||
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| Outdoor or indoor air restricted | Determine cause and correct | |
| or air is recirculating | ||
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| Low refrigerant charge | Check for leaks, repair and recharge | |
Head pressure too low. |
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Compressor valves leaking | Replace compressor | ||
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| Restriction in liquid tube | Remove restriction | |
| High heat load | Check for source and eliminate | |
Excessive suction pressure. |
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Compressor valves leaking | Replace compressor | ||
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| Refrigerant overcharged | Recover excess refrigerant | |
| Dirty air filter (cooling) | Replace Filter | |
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| Low refrigerant charge | Check for leaks, repair, and recharge | |
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| Metering device or low side restricted | Remove source of restriction | |
Suction pressure too low. | Insufficient indoor airflow (cooling) | Increase air quantity | |
Check filter- replace if necessary | |||
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| Temperature too low in conditioned area (cooling) | Reset thermostat | |
| Outdoor ambient below 40°F (cooling) | Install | |
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| Replace | ||
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Compressor runs but | Normally closed contacts on | Check condition of relay on board. | |
outdoor fan does not. | defrost board open | Replace board if necessary. | |
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