Chapter 6: Troubleshooting
Problem | Possible cause | Solution | |
| No power. | Check main disconnect, fuses, wiring, | |
| and power lead to unit. | ||
|
| ||
| Wrong voltage supplied to unit. | Voltage must be within plus or minus | |
| 10% of nameplate rating. | ||
|
| ||
| Defective on/off switch. | Replace. | |
Unit does not run. | Control circuit fuse blown. | Replace control circuit fuse. | |
Check transformer. | |||
| |||
|
| Check for a short circuit. | |
| Defective control transformer. | Replace. | |
| Piping flow switch circuit open. | Add water or water/glycol solution as | |
| required. | ||
|
| ||
| Pump motor off on overload. | Reset and test. | |
| High/Low thermostat set higher | Lower thermostat stage 1 set to 10°F | |
| than temperature of liquid in | (6°C) below the leaving temperature | |
| system. | you want. | |
| Defective High/Low thermostat. | Replace. | |
| Low refrigerant indicator on. | Check refrigerant charge. | |
|
| Sight glass should be clear and the | |
|
| moisture indicator should be green | |
| Refrigerant low pressure switch | while compressor is running. Bubbles or | |
| foaming is normal when the | ||
| contacts open. | ||
| pass solenoid is energized. Call for | ||
|
| ||
|
| service if bubbling is occurring and/or | |
|
| moisture indicator is yellow. | |
|
| Clean the air filters. | |
| Refrigerant | Check condenser fans for proper | |
| rotation. | ||
| on. | ||
Pump runs; compressor does not. | Check for dirty condenser. | ||
| |||
| Reset and test. | ||
|
| ||
| Fan motor out on overload. | Reset and test. | |
| Defective fan cycling control. | Replace. | |
| Defective fan motor. | Repair or replace. | |
|
| Allow time to cool and reset, then check | |
|
| for high/low | |
| Compressor internal overload or | plus or minus 10% of the nameplate | |
| fuses are open. | rating. | |
|
| Check for open fuses and loose | |
|
| compressor electrical connections. | |
| Compressor contactor holding coil | Repair or replace. | |
| open. | ||
|
| ||
| Defective pump motor to | Repair or replace. | |
| compressor auxiliary contact. | ||
|
| ||
| Broken wire in the compressor | Locate and repair. | |
| control circuit. | ||
|
| ||
Pump runs, compressor cycles at | Incorrect High/Low Thermostat | Lower set point to 10°F (6°C) below | |
short intervals. | setting. | desired leaving water temperature. |
Chapter 6: Troubleshooting | 41 of 78 |