COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
Problem | Possible Cause | Possible Solution |
| Low voltage | Check voltage at compressor. 115V & 230V |
| units will operate at 10% voltage variance | |
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| |
| Temperature not set cold enough or | Set temperature to lower than ambient |
| room air thermistor inoperative | temperature. Test thermistor and replace |
|
| if inoperative. |
| Compressor hums but cuts off on | Hard start compressor. Direct test compressor. |
Compressor | overload | If compressor starts, add starting components |
does not run | Open or shorted compressor | Check for continuity & resistance |
| windings | |
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| |
| Open overload | Test overload protector & replace if inoperative |
| Open capacitor | Test capacitor & replace if inoperative |
| Inoperative system button | Test for continuity in all positions. Replace if |
| inoperative | |
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| |
| Broken, loose or incorrect wiring | Refer to appropriate wiring diagrams to check |
| wiring. Correct as needed. | |
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Problem | Possible Cause | Possible Solution |
| Inoperative system button | Test button & replace user interface if inoperative |
| Broken, loose or incorrect wiring | Refer to applicable wiring diagram. Repair. |
Fan motor | Open capacitor | Test capacitor & replace if inoperative |
does not run | Fan speed button defective. | Replace user interface if inoperative |
| Inoperative fan motor | Test fan motor & replace if inoperative (be sure |
| internal overload has had time to reset) | |
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Problem | Possible Cause | Possible Solution |
| Undersized unit | Refer to industry standard sizing chart |
| Indoor ambient thermistor open | See alarms. Replace thermistor if necessary. |
| or shorted. | |
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| |
Does not cool or | Dirty filter | Clean as recommended in Owner’s Manual |
only cools slightly | Dirty or restricted condenser or | Use pressure wash or biodegradable cleaning |
| evaporator coil | agent to clean |
| Poor air circulation | Adjust discharge louvers. Use high fan speed |
| Low capacity - undercharge | Check for leak & make repair |
| Compressor not pumping properly | Check amperage draw against nameplate. If |
| not conclusive, make pressure test | |
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