Tempstar Defrost Control Board for T4H460GKD300 — OEM 1173636 | Ships Today

Overview

The Tempstar 1173636 Defrost Control Board is the OEM brain of the defrost cycle on the T4H460GKD300 heat pump. It monitors outdoor coil temperature and accumulated run time, then energizes the reversing valve and shuts the outdoor fan to melt frost off the coil before returning the unit to heating. When this board fails you typically see a heat pump that ices over, won't initiate or terminate defrost, runs auxiliary heat constantly, or shows no outdoor unit operation at all. Replacing a faulty defrost board restores efficient heating and prevents compressor damage from prolonged coil icing.

Specifications

Compatibility

Directly fits the Tempstar T4H460GKD300 heat pump and is shared across many ICP-family outdoor units sold under the Heil, Comfortmaker, and Tempstar brands. Always confirm the printed part number on your existing board matches 1173636 before installing.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the outdoor unit's control/access panel.
3. Document — Photograph every wire and terminal on the board before disconnecting anything.
4. Remove — Unplug the low-voltage harnesses and release the board from its standoffs or mounting screws.
5. Install — Snap the new 1173636 board onto the standoffs and reconnect each wire exactly per your photo.
6. Test — Restore power and confirm normal heating, then force a defrost cycle to verify reversing valve and fan operation.

Signs You Need a Replacement

• Outdoor coil ices over and never defrosts
• Auxiliary/emergency heat runs nonstop
• Defrost cycle won't start or won't terminate
• No outdoor unit operation in heat mode

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.