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This OEM defrost control board (part #1173636) governs the defrost cycle on your Tempstar T4H336GKD100 heat pump. In heating mode, frost accumulates on the outdoor coil; the defrost board tracks run time and coil temperature, then periodically reverses the system to melt the ice so heating efficiency is maintained. It also coordinates the reversing valve, condenser fan, and auxiliary heat through the cycle. A failed board lets the outdoor coil ice over and lose heating capacity, sticks the unit in defrost, or prevents switching between heating and cooling. Watch for a coil packed with ice or snow, no heat output, a fan that won't stop during defrost, or a reversing valve that won't engage.
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24 VAC |
| Function | Defrost timing, reversing valve & fan control |
Direct OEM replacement for the Tempstar T4H336GKD100 heat pump and 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.
Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.