ICP Control Board for WPH4604000RKB1 — Heat Pump Defrost Board | Ships Today

Overview

This genuine OEM control board (part 1178001) is the main circuit board that manages operation of your ICP Tempstar Heil WPH4604000RKB1 heat pump, including the defrost cycle that keeps the outdoor coil clear of ice in heating mode. The board reads the defrost thermostat and timer logic, energizes the reversing valve and outdoor fan, and sequences the compressor and auxiliary heat. When it fails, the heat pump may not defrost (allowing the outdoor coil to ice over), may not switch modes, may leave the fan or compressor running incorrectly, or may not respond to thermostat calls at all. Installing the exact OEM board restores correct sequencing and reliable defrost protection.

Specifications

Compatibility

Direct factory replacement for the defrost control board in the ICP Tempstar Heil WPH4604000RKB1 heat pump and related ICP-family heat pumps using the same control platform. Confirm the printed part number 1178001 on your existing board before installing.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker and verify zero voltage at the board with a multimeter.
2. Access — Remove the heat-pump control-panel cover.
3. Document — Photograph every harness, sensor, and 24V connection before disconnecting.
4. Remove — Unplug all connectors, release the board standoffs or screws, and lift out the old board.
5. Install — Seat the new board and reconnect each connector exactly as photographed.
6. Test — Restore power and confirm normal heating, cooling, fan, and defrost operation.

Signs You Need a Replacement

• Outdoor coil ices over because the unit never enters defrost.
• Heat pump will not switch between heating and cooling.
• Compressor or outdoor fan runs at the wrong time.
• No response to thermostat calls despite 24V control power.

Shipping & Returns

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