Tempstar Defrost Control Board for T4H460GKB100 — Heat Pump | Ships Today
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Overview
This OEM defrost control board (part #1173636) is the logic center for the heat-pump defrost cycle on your Tempstar T4H460GKB100. It monitors the coil temperature sensor and accumulated run time, then reverses the system into defrost mode to melt frost off the outdoor coil before returning to heating. A failed defrost board is a frequent cause of an outdoor unit that ices over solid in winter, short-cycles, never defrosts, or runs the reversing valve and auxiliary heat at the wrong times. Because the board coordinates the compressor, fan, reversing valve, and emergency heat, a faulty unit can mimic many other failures — making it a key diagnostic component to confirm and replace.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24 VAC |
| Application | Heat Pump Defrost Logic |
| Fit | OEM Replacement |
Compatibility
Direct OEM replacement for the Tempstar T4H460GKB100 heat pump and used across many ICP-family heat pumps sold under the Tempstar, Heil, Comfortmaker, and Arcoaire brands. Match the printed part number (1173636) and confirm the connector and terminal layout against your existing board before installing.
Installation Guide
- Safety First — Disconnect power at the outdoor disconnect and main breaker, then verify zero voltage with a multimeter.
- Access — Remove the service panel to expose the control box and the mounted defrost board.
- Document — Photograph every wire and connector position before removing anything.
- Remove — Unplug the connectors, transfer or note the defrost timing jumper/pin setting, and unscrew the old board from its standoffs.
- Install — Mount the new board, set the defrost timing pin to match the original, and reconnect each harness per your photo.
- Test — Restore power, initiate heating, and verify the unit cycles, the reversing valve energizes correctly, and a forced defrost completes normally.
Signs You Need a Replacement
- Outdoor coil ices over and never enters defrost
- Unit short-cycles or defrosts far too often
- Reversing valve or auxiliary heat activates at the wrong times
- No outdoor operation despite a valid call for heat
Shipping & Returns
Ships same day on orders placed before 3 PM CST. 30-day returns on unused parts. 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