Tempstar Defrost Control Board for T4H330GKE200 — OEM 1173636 Heat Pump | Ships Today

Overview

This is a genuine OEM defrost control board (part number 1173636) for the Tempstar T4H330GKE200 heat pump. The defrost control board is the brain of the heat pump's defrost cycle: it monitors the outdoor coil temperature and ambient conditions, then commands the unit to periodically reverse into defrost mode to melt frost and ice off the outdoor coil during heating operation. It coordinates the reversing valve, the condenser fan, and the timing intervals that keep the coil clear so the system can maintain heating efficiency in cold weather. When this board fails, the heat pump may run continuously with a frosted or iced-over outdoor coil, fail to initiate or terminate defrost, short-cycle, or lose heating capacity entirely. Operating on a 24V low-voltage control signal, this board is a direct factory replacement that restores correct defrost timing and sequencing.

Specifications

Compatibility

Engineered for the Tempstar T4H330GKE200 heat pump and shared ICP-family platforms sold under the Heil, ICP, and Comfortmaker brands that use the same factory control architecture. Always confirm the printed part number 1173636 against your existing board before ordering.

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 panel cover to expose the board.
3. Document — Photograph every wire and terminal connection before disconnecting anything.
4. Remove — Label and unplug each low-voltage and sensor lead, release the board's mounting standoffs or screws, and lift the old board out.
5. Install — Mount the new 1173636 board, then reconnect every wire and the coil sensor exactly per your photos.
6. Test — Restore power and initiate a test defrost cycle to confirm correct sequencing and termination.

Signs You Need a Replacement

• Outdoor coil ices over and never goes into defrost.
• Unit stays stuck in defrost or short-cycles between modes.
• Loss of heating capacity in cold weather.
• No 24V output to the reversing valve or fan during the defrost call.

Shipping & Returns

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