Heat Pump - Compressor not Operating

Heat Pump: YorkGuard VI

Re: Compressor not Operating

These heat pumps are equipped with a YorkGuard VI module which monitors and controls unit operation and defrost.

An X/L terminal on the YorkGuard module sends a signal inside to flash a diagnostic light at the thermostat.

► Unlike previous models, the YorkGuard VI does not flash the actual diagnostic code at the thermostat, only a code 2, 3 or 4 to indicate a "Soft" or "Hard" lockout.

CHECKOUT:

1. Check Outdoor Unit

• Make sure the thermostat is set correctly and calling for Heat.
• Remove the access panel of the outdoor unit.
  • Unit Operating --> Step 4. Check Previous Diagnostic Codes
• Check for 230V inlet power on the compressor contactor.
  • No Power --> Step 2. Check Breaker & Compressor
  • Power Present --> Step 3. Check Current Diagnostic Codes

2. Check Breaker & Compressor

• Pull the service disconnect switch.
• Check resistance between each leaving leg of the compressor contactor & ground.
  • Any resistance = Electrical Short --> Check Compressor
  • No Short --> Check Capacitor
• Check the unit breaker at the breaker panel and reset if necessary.
• Re-insert the service disconnect plug to restore power to the outdoor unit.
• Re-check for 230V on the contactor inlet.
  • No Power --> Loose or Burnt Wires in Disconnect or Bad Breaker

3. Check Current Diagnostic Codes

• Observe the two LED lights on the control board.
• See YorkGuard VI Status and Fault Codes

4. Check Previous Diagnostic Codes

• Turn the thermostat to the "Off" position.
• Press and release the "Last Error" button near the top of the YorkGuard board.
  • The board will display the last 5 diagnostic codes, starting with the most recent.
  • See YorkGuard VI Status and Fault Codes
    • When finished reviewing previous codes, be sure to clear the fault history before proceeding.
      • Press and hold the "Last Error" button until both LEDs flash two times.