Tempstar Defrost Control Board for T4H436GKA100 - OEM Heat Pump Board | Ships Today
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Overview
This OEM defrost control board (OEM part #1173636) is the brain of the Tempstar T4H436GKA100 heat pump's defrost cycle. It monitors the outdoor coil temperature sensor and a time/temperature defrost algorithm to decide when frost has built up on the outdoor coil, then commands the reversing valve, energizes the compressor, and de-energizes the outdoor fan to melt the ice. It also handles compressor anti-short-cycle timing and 24V control sequencing. When this board fails, the heat pump can ice over solid, fail to defrost, lock out the compressor, or run the auxiliary heat continuously and spike the electric bill.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost control board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24 VAC |
| Function | Defrost timing, reversing valve & compressor control |
| Fits Model | T4H436GKA100 |
Compatibility
Designed for the Tempstar T4H436GKA100 heat pump and used across the ICP family (Heil, Comfortmaker, Arcoaire) on units calling for the 1173636 defrost board. Confirm the board part number and connector layout against your existing board before ordering.
Installation Guide
- Safety First - Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
- Access - Remove the condenser control-box panel to reach the board.
- Document - Photograph every wire, connector, and the defrost timer pin setting before disconnecting.
- Remove - Unplug the harness connectors and the coil sensor, release the board standoffs, and lift the old board out.
- Install - Seat the new board on the standoffs, reconnect all connectors per your photos, and match the defrost timer pin setting.
- Test - Restore power and force or observe a defrost cycle to confirm proper reversing valve and fan operation.
Signs You Need a Replacement
- Outdoor coil ices over and never defrosts
- Heat pump stuck running auxiliary/emergency heat
- Compressor or reversing valve fails to switch during defrost
- No 24V output to the contactor on a call for heat or cool
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