Table 10—Troubleshooting—Cooling
SYMPTOM | CAUSE | REMEDY | |
| Power Failure | Call power company | |
| Fuse blown or circuit breaker tripped | Replace fuse or reset circuit breaker | |
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| Defective thermostat, contractor, transformer, or | Replace component | |
| control relay | ||
Compressor and condenser fan will not start. |
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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 temperature | ||
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| Faulty wiring or loose connections in compressor | Check wiring and repair or replace | |
| circuit | ||
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Compressor will not start but condenser fan | Compressor motor burned out, seized, or internal | Determine cause | |
overload open | Replace compressor | ||
runs. | |||
Defective run/start capacitor, overload, start relay | Determine cause and replace | ||
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| One leg of | Replace fuse or reset circuit breaker | |
| Determine cause | ||
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| Scroll compressor is rotating | Correct the direction of rotation by reversing the | |
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in the wrong direction | |||
there may be a low pressure differential. | to allow pressures to equalize. | ||
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| Refrigerant overcharge or undercharge | Recover refrigerant, evacuate system, and re- | |
| charge to capacities shown on nameplate | ||
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| Defective compressor | Replace and determine cause | |
| Insufficient line voltage | Determine cause and correct | |
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Compressor cycles | Blocked condenser | Determine cause and correct | |
(other than normally satisfying thermostat). | Defective run/start capacitor, overload or start | Determine cause and replace | |
| relay | ||
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| Defective thermostat | Replace thermostat | |
| Faulty | Replace | |
| 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 | |
| Thermostat set too low | Reset thermostat | |
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Compressor operates continuously. | Low refrigerant charge | Locate leak, repair, and recharge | |
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Leaking valves in compressor | Replace compressor | ||
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| Air in system | Recover refrigerant, evacuate system, and re- | |
| charge | ||
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| Condenser coil dirty or restricted | Clean coil or remove restriction | |
| Dirty air filter | Replace filter | |
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| Dirty condenser coil | Clean coil | |
Excessive head pressure. | Refrigerant overcharged | Recover excess refrigerant | |
Air in system | Recover refrigerant, evacuate system, and re- | ||
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| charge | ||
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| Condenser air restricted or air | Determine cause and correct | |
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| Low refrigerant charge | Check for leaks, repair and recharge | |
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Head pressure too low. | Compressor valves leaking | Replace compressor | |
| Restriction in liquid tube | Remove restriction | |
| High heat load | Check for source and eliminate | |
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Excessive suction pressure. | Compressor valves leaking | Replace compressor | |
| Refrigerant overcharged | Recover excess refrigerant | |
| Dirty air filter | Replace Filter | |
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| Low refrigerant charge | Check for leaks, repair, and recharge | |
| Metering device or low side restricted | Remove source of restriction | |
Suction pressure too low. | Insufficient evaporator airflow | Increase air quantity | |
Check filter- replace if necessary | |||
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| Temperature too low in conditioned area | Reset thermostat | |
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| Outdoor ambient below 40°F | Install | |
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| Replace |
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