Tempstar Defrost Control Board for T4H348GKA200 — OEM 1173636 | Ships Today
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Overview
This is the genuine OEM defrost control board (part number 1173636) for the Tempstar T4H348GKA200 heat pump. The defrost board is the brain of the outdoor unit in heating mode. It monitors the defrost thermostat and the time/temperature defrost cycle, energizes the reversing valve and compressor, and switches the unit into a defrost cycle to clear ice from the outdoor coil before returning to normal heating. A failed board is a frequent cause of an outdoor coil that ices over solid, a heat pump that never defrosts, no compressor or fan operation in heat mode, or erratic changeover behavior. Replacing the board with the factory part restores the correct defrost logic and component sequencing for this model.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil family) |
| Control Voltage | 24V |
| Function | Defrost timing, reversing valve and compressor sequencing |
| Fitment | OEM direct replacement |
Compatibility
Direct-fit replacement for the Tempstar T4H348GKA200 heat pump. The 1173636 board is shared across a range of ICP-built Tempstar, Heil, and Comfortmaker heat pumps of this series. Match the part number and connector layout to your existing board before ordering, as board revisions vary by production date.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter before touching the board.
- Access — Remove the condensing unit service panel to reach the control box.
- Document — Photograph every wire, terminal, and connector on the existing board before disconnecting anything.
- Remove — Label and disconnect the harnesses, then unclip or unscrew the old board from its standoffs.
- Install — Mount the new 1173636, then transfer each connection to the matching terminal per your photo, confirming the defrost-time pin/jumper setting matches the original.
- Test — Restore power, initiate a heat call, and verify normal operation and a correct forced or timed defrost cycle.
Signs You Need a Replacement
- Outdoor coil ices over and the unit never defrosts
- No compressor or outdoor fan operation in heating mode
- Erratic or stuck heat/cool changeover
- Visible burn marks, corrosion, 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