ICP Control Board for WPH4244000RKB1 — Defrost Circuit Board | Ships Today

Overview

This OEM circuit board (part #1178001) is the brain of the outdoor unit on the ICP/Tempstar/Heil WPH4244000RKB1 heat pump. It manages the defrost cycle, sequences the compressor contactor and reversing valve, monitors the defrost thermostat and timing, and protects the system through anti-short-cycle and time-delay logic. When the board fails, the heat pump can lose defrost entirely (causing the outdoor coil to ice over in heating), fail to switch between heating and cooling, or stop energizing the compressor altogether. Board faults often masquerade as compressor or sensor problems, so confirming board operation is a key diagnostic step.

Specifications

Compatibility

Direct OEM fit for the ICP/Tempstar/Heil WPH4244000RKB1 heat pump. Match the part number and connector layout to your existing board, as ICP-family defrost boards vary by platform and timing configuration.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker. Verify zero voltage with a multimeter.
2. Access — Remove the control-compartment service panel on the condensing unit.
3. Document — Photograph every connector, plug, and wire landing on the old board.
4. Remove — Unplug each harness, release the board standoffs/screws, and lift the board out.
5. Install — Seat the new board on the standoffs and reconnect each harness exactly per your photo; set any defrost-timing jumper to match.
6. Test — Restore power, run a heating and cooling call, and verify defrost initiation/termination and proper valve switching.

Signs You Need a Replacement

• Outdoor coil ices over and never goes into defrost
• Heat pump won't switch between heating and cooling
• Compressor or fan won't energize despite a valid call
• Visible scorching, burnt relays, or corroded traces on the board

Shipping & Returns

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