Tempstar Defrost Control Board for T4H342GKA200 — Heat Pump | Ships Today
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Overview
This is a genuine OEM defrost control board, ICP/Tempstar part number 1173636, engineered for the Tempstar T4H342GKA200 heat pump. The defrost control board is the brain of the outdoor unit during heating mode. It monitors coil temperature and accumulated run time, then initiates a defrost cycle to melt frost off the outdoor coil by reversing the refrigerant flow and pausing the outdoor fan. It also manages the reversing valve, compressor contactor signal, and 24V control logic between the indoor and outdoor sections. When this board fails, the heat pump may ice over in winter, fail to switch between heating and cooling, short-cycle, or lose communication with the thermostat entirely.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP) |
| Control Voltage | 24V |
| Function | Defrost timing, reversing valve & contactor control |
| Fitment | OEM Replacement |
Compatibility
Designed for the Tempstar T4H342GKA200 heat pump and related ICP-family outdoor units (Heil, Comfortmaker, Arcoaire, Day & Night) originally equipped with board 1173636. Match the board's part number, terminal layout, and connector style to your existing unit before installing.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage at the board with a multimeter.
- Access — Remove the condensing unit control-box service panel.
- Document — Photograph every wire, connector, and dip-switch/jumper setting before disconnecting.
- Remove — Unplug harnesses, release the mounting standoffs, and lift out the old board.
- Install — Seat the new 1173636, transfer all connectors per your photo, and match the defrost timing jumper to the original.
- Test — Restore power and confirm normal heating/cooling operation and a forced defrost cycle.
Signs You Need a Replacement
- Outdoor coil freezes over and never defrosts in heating mode
- Heat pump won't switch between heating and cooling
- Short-cycling or no response to thermostat calls
- Visible burn marks, swollen capacitors, or scorched relays on the board
Shipping & Returns
Ships same day before 3 PM CST. 30-day returns. 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