ICP Defrost Control Board for WPH4484000RKB1 — Heat Pump | Ships Today
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Overview
This genuine OEM control circuit board (Part #1178001) is the electronic brain of the ICP / Tempstar / Heil WPH4484000RKB1 heat pump condenser. On a heat pump, the defrost control board monitors outdoor coil temperature and run time, then commands a defrost cycle to melt frost off the outdoor coil — energizing the reversing valve, stopping the fan, and timing the cycle so the unit doesn't ice over in cold weather. It also coordinates the compressor contactor and reversing valve on each heat/cool call. When this board fails, you can see no defrost (coil icing), constant or short-cycling defrost, a unit that won't switch modes, or a completely dead condenser. Replacing the board restores correct sequencing and protects the compressor.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1178001 |
| Type | Defrost Control Circuit Board |
| Brand | ICP (Tempstar / Heil) |
| Control Voltage | 24 VAC |
| Function | Defrost timing, reversing valve & contactor control |
| Application | Heat Pump Condenser |
Compatibility
Built for the ICP WPH4484000RKB1 heat pump and compatible ICP-family condensers (Tempstar, Heil, Comfortmaker) using this defrost board. Match the part number and connector layout to your existing board before installing.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
- Access — Remove the condenser service panel to reach the control box.
- Document — Photograph every wire, plug, and the defrost-timing jumper/pin setting before disconnecting.
- Remove — Unplug the connectors, release the board standoffs, and lift out the old board.
- Install — Mount the new board, set the defrost timing pins to match the original, and reconnect every wire per your photo.
- Test — Restore power, run a heat and cool call, and verify normal operation and defrost initiation.
Signs You Need a Replacement
- Outdoor coil ices over with no defrost cycle
- Constant or rapidly short-cycling defrost
- Heat pump won't switch between heating and cooling
- Condenser completely dead with 24V present
Shipping & Returns
Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.
Shipping Information
- Orders placed before 3PM CST ship same business day
- Standard delivery: 2-5 business days
- Express shipping available at checkout
- Free shipping on orders over $75
- Tracking number emailed upon shipment
Return Policy
- 30-day returns on unused parts in original packaging
- Electrical parts (capacitors, contactors, control boards) are final sale once installed
- Email info@nationalhvacparts.com to initiate a return
- Refunds processed within 5-7 business days