TROUBLESHOOTING
SOLID STATE HEAT PUMP CONTROL TROUBLESHOOTING PROCEDURE
1.NOTE: A thorough understanding of the defrost cycle sequence is essential. Review that section earlier in this manual prior to troubleshooting the control. Turn on AC power supply to unit.
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 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.
CODES | FUNCTION |
Slow Blink | Normal Operation |
Fast Blink | Compressor Time Delay |
1 Blink | Low Pressure Switch Failure |
2 Blink | High Pressure Switch Failure |
| or Condensate Overflow |
| Switch Activated |
3 Blink | Defrost Mode Active |
4 Blink | High Pressure Soft Lockout |
TABLE 5
TROUBLESHOOTING
| Symptom |
| Description, Check & Possible Causes | What & How to Check / Repair | ||
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Compressor will | 1. Check for LED illumination. | Yes = go to Step #2; No = go to Step #3 | ||||
not start (heating | Is there an LED illuminated on the board (flashing)? | |||||
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or cooling) |
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2. Check for error codes. | Yes = go to Step #4; No = go to Step #8 | |||||
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| Is the LED flashing a Code? | ||||
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| 3. Check for power at board. | Yes = go to Step #13; No = go to Step #9 | |||
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| Is there 24 volts AC between R and C? | ||||
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| 4. Check codes. | Code "1", go to Step #6; Code "2", go to Steps #7A & #7B; Fast Blink, go to Step #5 | |||
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| What code is blinking? | ||||
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| 5. Compressor delay active. | Check for proper operation; if still needed, go back to Step #1. | |||
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| Wait for 5 minute delay or jump board's "speed up pins". | ||||
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| 6. Low pressure fault. | Check wiring circuit and unit pressures. | |||
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| 7A. | High pressure fault. | Check wiring circuit and unit pressures. | ||
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| 7B. | Condensate overflow fault. | Check upper indoor coil drains; check lower outdoor coil drains; check main drain line. | ||
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| 8. Check for Compressor input signal. | Yes = go to Step #10; No = go to Step #11 | |||
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| Is there 24 volts AC between Y and C? | ||||
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| 9. No power to board. | The unit either does not have unit voltage, the transformer is bad or the unit wiring is incorrect. | |||
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| 10. Check for Compressor output signal. | Yes = go to Step #12; No = go to Step #13 | |||
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| Is there 24 volts AC between CC & C? | ||||
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| 11. No "Y" compressor input signal. | Check thermostat wiring, incorrect phase of unit (see section on Phase Monitor), and finally | |||
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| unit wiring. | ||
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| 12. No "CC" compressor output signal. | Check compressor contactor for proper operation and finally check compressor. | |||
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| 13. | Faulty board. | Replace defrost board. | ||
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Fan outdoor motor | Heat pump control defective | Check across fan relay on heat pump control. | ||||
does not run |
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| Replace heat pump control. | |||
(cooling or heating |
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Motor defective | Check for open or shorted motor winding. Replace motor. | |||||
except during |
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Motor capacitor defective | Check capacitor rating. Check for open or shorted capacitor. Replace capacitor. | |||||
defrost) | ||||||
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Reversing valve | Heat pump control defective | Check for 24V between | ||||
does not energize |
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| 1. Check control circuit wiring. | |||
(heating only) |
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| 2. Replace heat pump control | |||
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| Reversing valve solenoid coil defective | Check for open or shorted coil. | |||
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| Replace solenoid coil. | ||
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Unit will not go | Temperature sensor or heat pump control defective | Disconnect temperature sensor from board and jumper across "SPEEDUP" terminals and "SEN | ||||
into defrost |
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| JMP" terminals. This should cause the unit to go through a defrost cycle within one minute. | |||
(heating only) |
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| 1. If unit goes through defrost cycle, replace temperature sensor. | |||
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| 2. If unit does not go through defrost cycle, replace heat pump control. | ||
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Unit will not come | Temperature sensor or heat pump control defective. | Jumper across "SPEEDUP" terminal. | ||||
out of defrost |
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| This should cause the unit to come out of defrost within one minute. | |||
(heating only) |
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| 1. If unit comes out of defrost cycle, replace temperature sensor. | |||
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| 2. If unit does not come out of defrost cycle, replace heat pump control. | ||
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Manual | |
Page | 51 of 59 |