OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
This genuine OEM control board (part #1178001) is the electronic brain of the ICP/Tempstar/Heil WPH4424000RKB1 heat pump. It manages defrost timing, reversing-valve operation, compressor and fan sequencing, time delays, and safety lockouts based on inputs from the thermostat and sensors. When the board fails, the unit may not start at all, skip defrost (causing outdoor coil icing), short-cycle, run the fan or compressor continuously, or throw erratic fault codes. Power surges, moisture, corroded relays, and burned traces are common causes. Installing the correct OEM board restores reliable sequencing and protects the compressor from improper cycling.
| Spec | Value |
|---|---|
| Part Number | 1178001 |
| Type | Defrost / Control Circuit Board |
| Brand | ICP (Tempstar / Heil) |
| Application | Heat Pump Outdoor Control |
Direct OEM replacement for the ICP/Tempstar/Heil WPH4424000RKB1. Match the board part number and connector layout to your existing board before installing — control boards are model-specific.
Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.