OEM Carrier Defrost Control Board HK32EA007 for Model PH4GEAB42000AA

This is the genuine OEM defrost control board for the Carrier PH4GEAB42000AA heat pump. The defrost control board manages timed and demand-initiated defrost cycles, commanding the reversing valve and outdoor fan to shed ice accumulation from the outdoor coil. When this board fails, the heat pump may run continuously in defrost, never enter defrost at all, display fault lockout codes, or lose heating capacity due to a fully iced-over coil — all symptoms that point directly to the HK32EA007 as the root cause.

• Part Number: HK32EA007 | Also cross-references: 1173636, 1177927 | Genuine Carrier OEM — not an aftermarket substitute
• OEM vs Generic: OEM boards use factory-calibrated defrost termination logic and timing circuits. Aftermarket boards may use approximated timing intervals, risking coil ice-over or compressor damage from premature or missed defrost cycles.
• Install Difficulty: 3/5 — Requires disconnecting 24V control wiring and line-voltage connections at the board. Tools needed: 1/4" nut driver, needle-nose pliers, phone camera (photograph all wiring before removal). Always disconnect power at the disconnect and breaker before handling. Verify defrost initiation and termination after install.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our climate-controlled parts warehouse.

Compatibility: Designed for the Carrier PH4GEAB42000AA heat pump split system. This board also cross-references OEM numbers 1173636 and 1177927 and is compatible across select Carrier, Bryant, and Payne heat pump platforms sharing the same defrost control architecture. Always verify your existing board's part number against your unit's wiring diagram before ordering. Our parts specialists are available to confirm fitment — contact us before you buy if you have any questions.