ICP Defrost Control Board for WCH3604GKA1 — Heat Pump | Ships Today

Overview

This OEM defrost control board (part #1173636) manages the defrost cycle on ICP Tempstar Heil model WCH3604GKA1 heat pump condensing units. In heating mode, the board monitors the defrost thermostat and an internal timer to determine when frost has built up on the outdoor coil, then reverses the cycle, stops the outdoor fan, and energizes the reversing valve to melt the ice before returning to normal operation. It also coordinates the compressor contactor and 24V control signals. When the board fails, the heat pump may ice over completely, fail to defrost, run defrost too often, or lose heating output entirely. A bad board can also leave the outdoor fan or compressor stuck off.

Specifications

Compatibility

Designed for ICP Tempstar Heil model WCH3604GKA1 and compatible ICP-family heat pumps (Comfortmaker, Arcoaire, KeepRite). Match the OEM part number and defrost-timer configuration to your unit before installing.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the control-panel cover on the condenser.
3. Document — Photograph every wire and connector and note the defrost-timer jumper/pin setting before disconnecting.
4. Remove — Unplug the harness connectors and unscrew the board from its standoffs.
5. Install — Mount the new board, set the defrost timer pins to match the original, and reconnect per your photo.
6. Test — Restore power, run a heating call, and confirm normal operation and a forced or timed defrost cycle.

Signs You Need a Replacement

• Outdoor coil ices over and never defrosts
• Defrost runs too frequently or at the wrong times
• Reduced or no heating output in heat-pump mode
• Outdoor fan or compressor stays off during a call

Shipping & Returns

Ships same day on orders placed before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.