Tempstar Defrost Control Board for T4H336GKD200 — Heat Pump Timer | Ships Today
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Overview
This OEM defrost control board (part #1173636) is the brain of the defrost cycle on your Tempstar T4H336GKD200 heat pump. In heating mode, frost builds on the outdoor coil; the defrost board monitors run time and coil temperature, then periodically reverses the system to melt that ice so the unit can keep heating efficiently. The board also coordinates the reversing valve, condenser fan, and auxiliary heat during the cycle. When this board fails, the outdoor coil ices over and the unit loses heating capacity, the system may stick in defrost, or the heat pump may not switch between heating and cooling at all. Symptoms include a coil packed with ice or snow, no heat output, a fan that won't shut off during defrost, or the reversing valve failing to engage.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24 VAC |
| Function | Defrost timing, reversing valve & fan control |
Compatibility
Direct OEM replacement for the Tempstar T4H336GKD200 heat pump. This board is shared across many ICP-family heat pumps sold under the Heil, Comfortmaker, and Tempstar brands. Confirm your existing board's part number and terminal layout against 1173636 before installing.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
- Access — Remove the condenser service panel to reach the control box.
- Document — Photograph every wire and connector on the board before removal.
- Remove — Unplug the connectors, release the board's standoffs or screws, and lift it out.
- Install — Seat the new board on its standoffs and reconnect each harness exactly as photographed.
- Test — Restore power, initiate a defrost (or force a test pin jumper) and confirm proper cycling.
Signs You Need a Replacement
- Outdoor coil iced or snow-packed with no automatic defrost
- Heat pump stuck in defrost or running it far too often
- No heat output even though the unit is energized
- Reversing valve or fan not responding during the cycle
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