ICP Control Board for WPH4304000RKB1 — Defrost/Heat Pump Circuit Board | Ships Today

Overview

This is a genuine OEM control circuit board (part number 1178001) for the ICP/Tempstar/Heil WPH4304000RKB1 heat pump. The control board is the brain of the outdoor unit — it manages defrost timing and termination, sequences the compressor and condenser fan, switches the reversing valve between heating and cooling, and protects the system through built-in delays and lockouts. When the board fails the heat pump can lose defrost, run continuously in one mode, short cycle, or stop responding to the thermostat entirely. Failure symptoms include no outdoor operation, ice that never clears off the coil, erratic mode switching, and blank or stuck status LEDs.

Specifications

Compatibility

Directly fits the ICP/Tempstar/Heil WPH4304000RKB1 heat pump condensing unit. As the OEM control board for this unit it is the exact replacement for the original; on matching ICP-family heat pumps, confirm the part number and connector layout 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 electrical service panel to reach the control board.
3. Document — Photograph every plug, terminal, and jumper position on the old board.
4. Remove — Unplug the connectors, release the standoffs/screws, and lift out the board.
5. Install — Seat the new board, set any jumpers to match, and reconnect every plug per your photo.
6. Test — Restore power, run a heating and cooling cycle, and verify defrost and mode switching operate correctly.

Signs You Need a Replacement

• Outdoor unit does not run in heating or cooling.
• Coil ices over and defrost never initiates or terminates.
• Compressor short cycles or the reversing valve won't switch.
• Status LED is dead, stuck, or flashing a board-fault code.

Shipping & Returns

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