HEAT / COOL ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
Problem | Possible Cause | Action | |
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| Disconnect power to unit. Remove resistor | |
| Heat anticipator (resistor) shorted | from | |
| (on applicable models) | operate. Feel resistor for heat. If not heat, | |
Room temperature |
| replace resistor | |
uneven | Wide differential - partial loss of | Replace | |
(Heating cycle) | |||
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| Refer to appropriate wiring diagram. Resistor | |
| Incorrect wiring | is energized during "ON" cycle of compressor | |
|
| or fan. |
Problem | Possible Cause | Action | |
| Incorrect wiring | Refer to appropriate wiring diagram | |
| Defrost control timer motor not | Check for voltage at "TM" & "TM1" on timer. If | |
| advancing (applicable models) | no voltage, replace control | |
| Defrost control out of calibration | If outside coil temperature is 25F or below, & | |
| preselected time limit has elapsed, replace | ||
| (applicable models) | ||
Unit will not defrost | defrost control | ||
| |||
| If contacts remain closed between terminals | ||
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| Defrost control contacts stuck | "2" & "3" of the defrost control after | |
| preselected time interval has passed, replace | ||
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| ||
|
| control | |
| Defrost control bulb removed from | Reinstall & be assured that good bulb to coil | |
| or not making good coil contact | contact is made |
Problem | Possible Cause | Action | |
| Exhaust or fresh air door open | Check if operating properly. Instruct customer | |
| on proper use of control | ||
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| ||
| Dirty fi lter | Clean as recommended in Owner's Manual | |
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| Check heat rise across coil. If unit operates | |
| Unit undersized | effi ciently, check if insulation can be added | |
| to attic or walls. If insulation is adequate, | ||
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Does not heat |
| recommend additional unit or larger one | |
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adequately | Outdoor | ||
control. If temperature is below 38°F, replace | |||
| models) | ||
| control | ||
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| Heater | Check for adequate fan air across heater. | |
| Check control for open at 160°F & close at | ||
| off | ||
| 150°F | ||
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| Shorted supplementary heater | Ohmmeter check, approx. | |
| Incorrect wiring | Check applicable wiring diagram |
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