Tempstar Defrost Control Board for T4H324GKD100 — Heat Pump | Ships Today
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Overview
This OEM defrost control board (part number 1173636) is the genuine electronic brain for the Tempstar T4H324GKD100 heat pump's defrost cycle. It monitors the outdoor coil temperature sensor and the defrost timer interval, then commands the reversing valve, condenser fan, and auxiliary heat to clear frost and ice from the outdoor coil during cold-weather heating. When the board fails, the unit may ice over completely, run continuous or never-ending defrosts, fail to switch into heating, or lock the compressor out. Boards commonly fail from power surges, lightning, moisture intrusion, and burned relay contacts.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24V |
| Application | Heat Pump Defrost Control |
Compatibility
Built for the Tempstar T4H324GKD100 heat pump and ICP-family heat pumps using the same defrost board platform. Tempstar, Heil and Comfortmaker share common controls, so this board cross-fits many sibling models — match the printed part number 1173636 and the board's connector layout to your existing board before installing.
Installation Guide
- Safety First — Disconnect power at the outdoor disconnect and verify zero voltage with a multimeter before touching the board.
- Access — Remove the control-panel service cover to expose the defrost board.
- Document — Photograph every harness connector and the defrost-timer jumper/pin setting.
- Remove — Unplug each connector, release the board standoffs/screws, and lift the old board out.
- Install — Mount the new board, set the defrost timer jumper to match the original, and reseat every connector per your photo.
- Test — Restore power and confirm normal heating operation; force a defrost test to verify the cycle initiates and terminates.
Signs You Need a Replacement
- Outdoor coil ices over and never defrosts in heating mode
- Unit stuck in continuous defrost or won't enter heating
- No 24V output to the reversing valve or fan during defrost
- Visible burn marks, corrosion, or a fried relay on the board
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