Tempstar Defrost Control Board for T4H348GKE200 — Heat Pump | Ships Today
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Overview
This OEM defrost control board (part #1173636) is the brain of your Tempstar T4H348GKE200 heat pump's defrost cycle. In heating mode, frost builds on the outdoor coil; the board monitors coil temperature and elapsed run time, then commands a defrost cycle by reversing the valve, shutting off the outdoor fan, and energizing auxiliary heat so the coil clears without blowing cold air indoors. It also coordinates compressor timing and lockout protection. When this board fails, the heat pump may ice over completely, run defrost too often (or never), short-cycle, or refuse to switch between heating and cooling. Symptoms like a frozen outdoor unit in winter or a reversing valve that won't shift usually trace back to a failed defrost board.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24V |
| Function | Defrost timing, reversing valve & fan control, compressor timing |
| Fitment | OEM |
Compatibility
Engineered for the Tempstar T4H348GKE200 heat pump and shared across matching ICP, Heil, and Comfortmaker heat-pump platforms that use this defrost board. Match the printed part number on your existing board before ordering.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then confirm zero voltage with a multimeter.
- Access — Remove the control/electrical access panel on the outdoor unit.
- Document — Photograph every wire and connector position on the existing board.
- Remove — Unplug the harness connectors and unscrew or unclip the board from its standoffs.
- Install — Seat the new board on the standoffs and reconnect each harness exactly as photographed.
- Test — Restore power and verify a normal heating call and, if conditions allow, a forced defrost cycle.
Signs You Need a Replacement
- Outdoor coil freezes solid and never defrosts in heating mode
- Constant or excessively frequent defrost cycling
- Heat pump won't switch between heating and cooling
- Visible burn marks, corrosion, or failed relays on the board
Shipping & Returns
Ships same day on orders placed before 3 PM CST. 30-day hassle-free 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