ICP Defrost Control Circuit Board for WPH3424000RKC1 — OEM | Ships Today

Overview

This is the genuine OEM control circuit board (Part No. 1178001) for the ICP/Tempstar/Heil WPH3424000RKC1 heat pump. The board is the brain of the outdoor unit — on a heat pump it manages the defrost cycle, monitors the coil temperature sensor, sequences the reversing valve and auxiliary heat, and controls the compressor contactor and outdoor fan timing. A failed control board can cause a no-defrost condition with ice buildup on the outdoor coil, a unit that won't start, erratic mode switching, or a compressor that short-cycles. Because the board coordinates safety timers and defrost logic, a faulty board often shows up as poor heating performance in cold weather.

Specifications

Compatibility

Built as the factory replacement control board for the ICP/Tempstar/Heil WPH3424000RKC1 heat pump condensing unit. Control boards are model-specific — confirm the exact part number on your existing board and the connector layout before installing.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter before handling the board.
2. Access — Remove the condensing unit control-panel cover.
3. Document — Photograph every plug, sensor, and wire on the old board before disconnecting.
4. Remove — Unplug the connectors, release the board standoffs or mounting screws, and lift the old board out.
5. Install — Seat the new board on its standoffs and reconnect every harness exactly per your photo.
6. Test — Restore power, run a heating and cooling call, and force a defrost test to confirm correct sequencing.

Signs You Need a Replacement

• Outdoor coil ices over with no defrost cycle.
• Unit won't start or randomly short-cycles.
• Reversing valve or fan timing behaves erratically.
• Visible burnt traces, relays, or scorch marks on the board.

Shipping & Returns

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