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TROUBLESHOOTING
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| TABLE 5 | |
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| TROUBLESHOOTING | |
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Symptom | Possible Causes | What & How to Check / Repair | |
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Compressor will | Check for 24V from R to C | If 24V is not present at R, check wiring from board to transformer and check transformer input | |
not start (heating | on the heat pump control | and output voltage. If transformer has no 24V output, determine cause and replace | |
or cooling) |
| transformer. | |
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| Check for 24V from Y to C | If 24V is not present, check thermostat and thermostat wiring, outdoor thermostat (if equipped) | |
| on low voltage terminal strip | phase monitor (if equipped, used on some | |
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| next step. | |
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| Check for 24V from C to | If 24V is present, check and/or replace compressor contactor. If 24V is not present, jump the | |
| CC on heat pump control | speed up terminal for 10 seconds. If compressor does not start check for 24V from C to L1 | |
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| on the heat pump control. | |
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| Compressor lock out | If 24V is not present at L1 of the heat pump control, check the high pressure switch and low | |
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| pressure bypass relay (if equipped) and all associated wiring and terminals. The safety circuit | |
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| is a closed circuit. If the high pressure switch or low pressure bypass relay are open, the | |
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| control will lock out the compressor. Replace defective component. Cycle power off and on to | |
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| reset lock out. Jump speed up terminals for 10 seconds to override | |
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| Defective heat pump control | If 24V is present from C to Y, and C to L1 on the heat pump control, the time delay has been | |
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| overridden or expired and no 24V is present at CC, replace the heat pump control. | |
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Fan outdoor motor | Heat pump control defective | Check across fan relay on heat pump control. | |
does not run |
| 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 |
| 1. Check control circuit wiring. | |
(heating only) |
| 2. Replace heat pump control | |
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| Reversing valve solenoid | Check for open or shorted coil. | |
| coil defective | Replace solenoid coil. | |
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Unit will not go | Temperature sensor or heat | Disconnect temperature sensor from board and jumper across "SPEEDUP" terminals and "SEN | |
into defrost | pump control defective | JMP" terminals. This should cause the unit to go through a defrost cycle within one minute. | |
(heating only) |
| 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 | Jumper across "SPEEDUP" terminal. | |
out of defrost | pump control defective. | This should cause the unit to come out of defrost within one minute. | |
(heating only) |
| 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 | 28 of 34 |