ICP Defrost Control Board for WCH3422GKA1 — OEM Heat Pump | Ships Today
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Overview
This OEM defrost control board (part 1173636) is the brain of the heat-pump defrost cycle on your ICP / Heil / Tempstar / Comfortmaker WCH3422GKA1. In heating mode, frost builds on the outdoor coil and chokes off airflow; the defrost board monitors the defrost thermostat (and timing intervals) and, when needed, reverses the unit into a brief cooling cycle to melt the ice, energizing the reversing valve and stopping the outdoor fan until the coil clears. When this board fails, the unit can ice over solid, run inefficiently, short-cycle, or never enter/exit defrost properly. Symptoms range from a frozen outdoor coil in winter to no compressor or fan operation at all. This is a direct OEM replacement that restores correct defrost timing and reversing-valve control.
Specifications
| Spec | Value |
|---|---|
| OEM Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | ICP (Heil / Tempstar / Comfortmaker) |
| Control Voltage | 24 VAC |
| Application | Heat Pump Defrost / Reversing Valve Control |
| Fitment | OEM Direct Replacement |
Compatibility
Direct OEM replacement for the WCH3422GKA1 heat pump and other ICP-family outdoor units using this defrost control 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; verify zero voltage with a multimeter.
- Access — Remove the condenser control-panel cover to expose the board.
- Document — Photograph every wire harness and terminal position on the old board.
- Remove — Unplug the connectors, release the standoffs/screws, and lift the old board out.
- Install — Seat the new board on its standoffs and reconnect every harness exactly per your photo, including the defrost thermostat leads.
- Test — Restore power, run a heating call, and verify normal operation; you can initiate a forced defrost per the model's service jumper to confirm the board functions.
Signs You Need a Replacement
- Outdoor coil ices over and never defrosts in heating mode.
- Unit short-cycles or won't switch into/out of defrost.
- No compressor or outdoor fan operation on a heat call.
- Visible burnt traces, scorched relays, or corrosion on the board.
Shipping & Returns
Ships same day on orders placed before 3 PM CST. 30-day returns on unused parts. 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