Tempstar Defrost Control Board for T4H348GKE100 — OEM Part 1173636 | Ships Today
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Overview
This is the genuine OEM defrost control board (part number 1173636) for the Tempstar T4H348GKE100 heat pump. The defrost board is the brain of the outdoor unit during heating mode. It monitors coil temperature and run time, then commands a defrost cycle to clear frost and ice from the outdoor coil so the system can keep pulling heat from the air. It also coordinates the reversing valve, condenser fan, and compressor timing, and provides anti-short-cycle protection on the 24V control circuit. When this board fails you will often see the unit ice over and never defrost, run defrost constantly, fail to switch between heating and cooling, or stop responding to the thermostat entirely.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1173636 |
| Type | Defrost Control Board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24V |
| Application | Heat Pump Outdoor Unit |
| Fit | OEM Replacement |
Compatibility
Engineered as the factory replacement for the Tempstar T4H348GKE100 heat pump. Because Tempstar, Heil, Comfortmaker, and other ICP-built units share components, this board number is also used across related ICP outdoor models. Always confirm part number 1173636 against the board printed on your existing control before ordering.
Installation Guide
- Safety First — Disconnect power at the outdoor disconnect and breaker, then verify zero voltage with a multimeter.
- Access — Remove the control panel cover on the outdoor unit.
- Document — Photograph every wire and terminal on the existing board before disconnecting anything.
- Remove — Label and disconnect the low-voltage and line-voltage leads, release the board standoffs or screws, and lift out the old board.
- Install — Mount the new board on the same standoffs and reconnect each wire exactly as photographed, matching the defrost timer pin setting.
- Test — Restore power, run a heating cycle, and confirm a normal defrost and reversing-valve changeover.
Signs You Need a Replacement
- Outdoor coil ices over and the unit never enters defrost.
- System runs defrost constantly or short-cycles between modes.
- Heat pump will not switch between heating and cooling.
- No 24V output to the contactor or reversing valve.
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