TROUBLESHOOTING
Heat Pump Fails to Operate Properly |
| LED Description |
Review “Sequence of Operation” and visually inspect the heat pump before troubleshooting:
WARNING
Electrical Shock Hazard
Disconnect power before servicing.
Replace all parts and panels before operating.
Failure to do so can result in death or electrical shock.
System Diagnostic Module
W4GH6 heat pumps contain a diagnostic module for troubleshooting heat pump system failures. By monitoring and analyzing data from the compressor and thermostat demand, the module can accurately detect the cause of electrical and system related failure without any sensors. If a system problem occurs, a flashing LED indicator communicates the failure code.
Power LED (Green) indicates voltage is present at the power connection of the module.
Alert LED (Yellow) communicates an abnormal system condition through a unique flash code. The Alert LED will flash a number of times consecutively, pause, and then repeat the process. The number of consecutive flashes correlates to a particular abnormal condition.
Trip LED (Red) indicates there is a demand signal from the thermostat but no current to the compressor is detected by the module. The Trip LED typically indicates the compressor protector is open or may indicate missing supply power to the compressor.
Diagnostic LEDs Interpretation
When an abnormal system condition occurs, the diagnostic module displays the appropriate Alert and/or Trip LED. The yellow Alert LED will flash a number of times consecutively, pause, and then repeat the process. To identify a flash code number, count the number of consecutive flashes. Refer to the Flash Codes chart for information on the flash codes.
Every time the module powers up, the last Alert LED flash code that occurred prior to shutdown is displayed for 60 seconds. The module will continue to display the previous flash code until the condition returns to normal or 24 VAC is removed from the module. Trip and Alert LED’s flashing at the same time means control circuit voltage is too low for operation.
Flash Codes
LED Status | Fault Description | Troubleshooting Information |
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Power (Green) | Module has power. | ■ Supply voltage is present at module terminals. |
Trip (Red) | Thermostat demand signal Y1 |
| is present, but the |
| compressor is not running. |
■Compressor protector is open.
■Outdoor unit power disconnect is open.
■Compressor circuit breaker or fuse(s) is open.
■Broken wire or connector is not making contact.
■Low pressure switch is open, if present in system.
■Compressor contactor has failed to open.
Alert (Yellow) Flash Code 1 | Long Run Time: Compressor |
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| is running extremely long run |
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| cycles. |
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| NOTE: Not applicable on heat |
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| pump models. |
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Alert (Yellow) Flash Code 2 | System Pressure Trip: | ■ | High head pressure. |
| Discharge or suction pressure | ■ | Condenser coil has poor air circulation (dirty, blocked, |
| out of limits or compressor is | ||
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| damaged). | |
| overloaded. |
| |
| ■ | Condenser fan is not running. | |
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■ Return air duct has substantial leakage.
■ If low pressure switch is present in the system, go to Flash Code 1 information.
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