Goodman GPH13 - Contactor Won't Energize

Goodman Package Heat Pump

Re: Contactor Won't Energize

The thermostat is calling and 24VAC power is present on "Y" but the contactor will not engage.

► The Goodman GPH13 package heat pump breaks "Common" to the contactor through the High and Low Pressure Switches.

►If the pressure safeties are "closed" the contactor should energize as soon as 24VAC is present on "Y" (no time delays).

CHECKOUT:

1. Check High Voltage Power

• Remove power from the unit by pulling the service disconnect or by turning off power at the breaker.
  • IMPORTANT! It is very common to have multiple power supplies to a heat pump package unit.
• Open the service access panel and inspect for any burnt wiring.
• Re-apply power to the unit.
• Check for 230VAC across L1 and L2 of the compressor contactor.
  • No Power ⇒ Check Disconnect and Breakers

2. Check Low Voltage Power

• Set the thermostat to call for either heating or cooling.
• At the low voltage wiring connections of the outdoor unit, check for 24VAC between "R" (Red) and "C" (Blue).
  • No Power = Bad Transformer/Blown fuse or Loose Wiring
• Check for 24VAC between "Y"  Yellow  and "C"  Blue .
  • No Power = No Call from Thermostat ⇒ Recheck Stat
• Check for 24VAC across both sides of the compressor contactor coil.
  • Power Present but not Engaged = Bad Contactor
  • No Power at Contactor but Power on "Y" = Open Safety Circuit → Step 3. Check Refrigerant Charge

3. Check Refrigerant Charge

• Hook-up refrigerant gauges to the unit and observe pressure readings.
  • Low Pressure Switch should open below 10 psig.
  • High Pressure Switch should open above 450 psig.

4. Test Safety Circuit

• Important Note! Remember that the safeties break the "Common" side of 24VAC power.
• Check for 24VAC power between "Y"  Yellow  and the "YL/PK"  Yellow/Pink  wire at the transformer. *("Yellow" on 5 ton model)
  • No Power = No Call from Thermostat ⇒ Recheck Stat
• If there is no connector, "Skin" a small section of the connector wire between the Low Pressure Switch and the High Pressure Switch.
• Check for 24VAC between "Y" (Yellow) and the skinned section of wire (or at the connector) between the pressure safeties.
  • No Power Present = Open Low Pressure Switch
  • Power Present ⇒ Recheck for 24VAC at contactor.
    • No Power at Contactor + Power at Connector Wire = Open High Pressure Switch