OEM Carrier Defrost Control Board HK32EA008 for Model PH4GPAA42000AA

This is the factory OEM defrost control board for the Carrier PH4GPAA42000AA heat pump. The defrost control board manages the automatic defrost cycle — monitoring outdoor coil temperature and run time to periodically reverse the refrigerant flow and melt accumulated ice. When this board fails, the outdoor unit coil will freeze over solid, heating capacity drops dramatically, and the system may lock out entirely. Replacing it with the correct OEM board restores factory-calibrated defrost timing and protects the compressor from long-term damage caused by sustained ice buildup.

• OEM Part Number: HK32EA008 | Replaces superseded part HK32EA003 | Factory-direct Carrier replacement
• OEM vs Generic: The OEM board uses factory-programmed defrost timing algorithms matched to the PH4GPAA42000AA refrigerant circuit. Aftermarket boards may use generic timer intervals that leave coils under- or over-defrosted, reducing efficiency and compressor life.
• Install Difficulty: 3/5 — Requires isolating 240V power at the disconnect before accessing the control panel. Label all low-voltage wiring connections (typically R, C, Y, W, O/B, and defrost thermostat leads) before removal. Tools needed: insulated screwdrivers, needle-nose pliers, and a multimeter to verify 24V control circuit continuity post-install.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier PH4GPAA42000AA packaged heat pump. This board also replaces the earlier HK32EA003 per Carrier's supersession. Always verify your existing board's part number on the board label before ordering. Our fitment team is available to confirm compatibility — contact us before you order.