ICP Defrost Control Board for WCH3424GKA1 — Heat Pump 24V | Ships Today

Overview

This OEM defrost control board (part #1173636) is the brain of the defrost cycle on the ICP WCH3424GKA1 heat pump. It monitors outdoor coil temperature and accumulated run time, then commands the reversing valve and condenser fan to clear frost and ice from the outdoor coil during heating operation. The board also manages compressor timing and anti-short-cycle protection. When this board fails, the heat pump loses its ability to defrost properly — the outdoor coil ices over, heating capacity drops, and the system may trip on high head pressure. Symptoms range from a coil caked in ice to a heat pump that runs constantly without warming the home.

Specifications

Compatibility

Direct OEM replacement for the ICP / Tempstar / Heil WCH3424GKA1 heat pump condensing unit and related ICP-family models using this defrost board. Verify the part number against your existing board before ordering.

Installation Guide

1. Safety First — Disconnect power at the breaker and outdoor disconnect; verify zero voltage with a multimeter.
2. Access — Remove the condenser control panel to expose the board.
3. Document — Photograph every connector, sensor, and wire position before unplugging.
4. Remove — Unplug the harnesses and defrost sensor, then release the board from its standoffs.
5. Install — Snap in the new board, reconnect all harnesses and the coil sensor per your photo.
6. Test — Restore power, initiate a defrost (or forced defrost per the unit), and confirm the reversing valve shifts and the fan cycles correctly.

Signs You Need a Replacement

• Outdoor coil ices or frosts over and never clears.
• Heat pump fails to switch into defrost during cold, damp weather.
• Reversing valve or condenser fan won't respond on a defrost call.
• Erratic compressor cycling or no 24V output to the controlled components.

Shipping & Returns

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