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This OEM defrost control board (part 1173636) is the brain of the Tempstar T4H736GKA100 heat pump's defrost cycle. It monitors coil temperature and run time, then triggers a defrost cycle — energizing the reversing valve, stopping the outdoor fan, and activating auxiliary heat — to clear frost from the outdoor coil in cold weather. When the board fails, the heat pump either never defrosts (ice builds up on the coil and efficiency collapses) or defrosts constantly. Symptoms include a frozen outdoor coil, no heat or weak heat, the outdoor fan behaving erratically, or no response to a defrost call.
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil) |
| Function | Defrost timing, reversing valve & fan control |
| Control Voltage | 24V |
| Application | Heat Pump |
Designed for the Tempstar T4H736GKA100 heat pump and matching ICP / Heil / Comfortmaker units that use the 1173636 defrost board. Always match the exact part number on your existing board, as defrost boards vary by platform and timing scheme.
Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.