Tempstar Defrost Control Board for T4H436GKD100 — OEM 1173636 Heat Pump Board | Ships Today
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Overview
The OEM defrost control board (part number 1173636) governs the defrost cycle on your Tempstar T4H436GKD100 heat pump. It monitors outdoor coil temperature and run time, then commands the reversing valve and outdoor fan to clear frost and ice from the condenser coil in cold weather. A faulty defrost board is a frequent culprit behind a heat pump that ices up, blows cold air in heating mode, or short-cycles. This genuine OEM-spec board is built to the original 24V control standard for dependable, fault-free defrost operation.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar |
| Control Voltage | 24V |
| Application | Heat Pump Defrost Control |
| Fitment | OEM Replacement |
Compatibility
Direct-fit replacement for the Tempstar T4H436GKD100 heat pump condensing unit. This board is also shared across many ICP/Heil-built heat pump platforms using OEM part 1173636. Verify the part number on your existing board before ordering.
Installation Guide
- Safety First — Disconnect power at the breaker and disconnect, then verify zero voltage with a multimeter at the board terminals.
- Access — Remove the control-panel service cover on the outdoor unit.
- Document — Photograph every wire and terminal location before disconnecting anything.
- Remove — Label and unplug the low-voltage connectors, release the board standoffs/screws, and lift out the old defrost board.
- Install — Mount the new 1173636 board, reconnect all wires exactly per your photo, and set any defrost-interval pins to match the original.
- Test — Restore power, run a heating cycle, and confirm the unit enters and exits defrost correctly.
Signs You Need a Replacement
- Outdoor coil freezes over and never clears in heating mode
- Heat pump blows cold air or fails to switch to defrost
- Unit short-cycles or the reversing valve won't energize
- Visible burnt traces, scorching, or corrosion 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