TROUBLESHOOTING
SOLID STATE HEAT PUMP CONTROL TROUBLESHOOTING PROCEDURE
1.Turn on AC power supply to indoor and outdoor units.
2.Turn thermostat blower switch to fan on. The indoor blower should start. (If it doesn’t, troubleshoot indoor unit and correct problem.)
3.Turn thermostat blower switch to auto position. Indoor blower should stop.
4.Set system switch to heat or cool. Adjust thermostat to call for heat or cool. The indoor blower, compressor, and outdoor fan should start.
NOTE: If there was no power to 24 volt transformer, the compressor and outdoor fan motor will not start for 5 minutes. This is because of the compressor short cycle protection.
TABLE 5
TROUBLESHOOTING
SYMPTOM | POSSIBLE CAUSES |
| WHAT TO CHECK |
| HOW TO CHECK OR REPAIR | |
|
|
|
| |||
Compressor | Control circuit wiring | Check for R connection at unit | Run R connection to outdoor unit to power heat | |||
contactor does not |
| and 24 volt between R - C | pump control. | |||
energize (heating or |
|
|
|
|
| |
Compressor lock out | 1. | Check for 24V between | 1. | If no voltage between | ||
cooling). |
|
|
| off and on again to reset high pressure | ||
|
|
|
| |||
|
|
|
|
| switch. | |
|
| 2. | Check across high | 2. | If high pressure switch is open and will not | |
|
|
| pressure switch |
| reset, replace high pressure switch. | |
|
|
|
| |||
| Compressor short cycle | Check for 24 V between | If no voltage between | |||
| protection | and | terminal, and within 10 seconds power should | |||
|
|
|
| appear between | ||
|
|
|
| jumper after 10 seconds. | ||
|
|
|
| |||
| Heat pump control | Check all other possible | Replace heat pump control. | |||
| defective | causes. Manual |
|
| ||
|
|
|
| |||
| Contactor defective | Check for open or shorted coil | Replace contactor. | |||
|
| winding. |
|
| ||
|
|
|
| |||
| Power phasing not | Check for red LED on phase | Switch two power leads to the unit. | |||
| correct | monitor (3 phase units only). |
|
| ||
|
|
|
| |||
Fan outdoor motor | Motor defective | Check for open or shorted | Replace motor. | |||
does not run |
| motor winding. |
|
| ||
(cooling or heating |
|
|
|
|
| |
Motor capacitor | Check capacitor rating. Check | Replace capacitor. | ||||
except during | ||||||
defective | for open or shorted capacitor. |
|
| |||
defrost). |
|
| ||||
|
|
|
|
| ||
Heat pump control | Check across fan relay on | Replace heat pump control. | ||||
| ||||||
| defective | heat pump control |
|
| ||
|
|
|
| |||
Reversing valve | Reversing valve solenoid | Check for open or shorted coil. | Replace solenoid coil. | |||
does not energize | coil defective |
|
|
|
| |
(heating only). |
|
|
|
|
| |
Heat pump control | Check for 24V between | 1. | Check control circuit wiring. | |||
| ||||||
| defective | and | 2. | Replace heat pump control. | ||
|
|
|
|
| ||
Unit will not go into | Temperature sensor or | Disconnect temperature | 1. | If unit goes through defrost cycle, replace | ||
defrost | heat pump control | sensor from board and jumper |
| temperature sensor. | ||
(heating only). | defective | across speed up terminals and |
|
| ||
|
| sen jump terminals. This | 2. | If unit does not go through defrost cycle, | ||
|
| should cause the unit to go |
| replace heat pump control. | ||
|
| through a defrost cycle within |
|
| ||
|
| one minute. |
|
| ||
|
|
|
|
| ||
Unit will not come | Temperature sensor or | Jumper across speed up | 1. | If unit comes out of defrost cycle, replace | ||
out of defrost | heat pump control | terminals. This should cause |
| temperature sensor. | ||
(heating only). | defective | the unit to come out of defrost | 2. | If unit does not come out of defrost cycle, | ||
|
| within one minute. |
| replace heat pump control. | ||
|
|
|
|
|
| |
|
|
|
|
|
| |
Manual | |
Page | 20 of 25 |
