Tempstar Control Board for T4A436GKD100 — ComfortAlert Diagnostic Module | Ships Today
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Overview
This is a genuine OEM ComfortAlert control board (OEM part #1177402) for the Tempstar T4A436GKD100 condensing unit. The ComfortAlert module continuously monitors compressor electrical operation and reports fault conditions — locked rotor, open circuit, low voltage, short cycling, and welded contactor — through a diagnostic LED, giving technicians a fast read on system health without a full teardown. By guarding the compressor against repeated fault-condition starts, this board extends compressor life and cuts troubleshooting time. When it fails, you may get no diagnostic feedback, a unit that ignores a cooling call, or erratic compressor protection behavior. Replacing it restores proper monitoring and the protective lockouts that keep the compressor safe.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1177402 |
| Type | ComfortAlert Diagnostic Control Board |
| Brand | Tempstar (ICP / Heil) |
| Control Voltage | 24V |
| Function | Compressor diagnostics, protection & fault LED |
Compatibility
Designed as a direct-fit replacement for the Tempstar T4A436GKD100 air conditioning condenser. The same ComfortAlert module is shared across many ICP-family condensers and heat pumps (Heil, Comfortmaker, Arcoaire) of the same generation. Verify the part number on your existing board before ordering.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then confirm zero voltage at the board with a multimeter.
- Access — Remove the condenser service panel to reach the control box.
- Document — Photograph every low-voltage and sensing lead and its terminal position on the board.
- Remove — Unplug the harness connectors, release the mounting standoffs or screws, and lift out the old board.
- Install — Seat the new board on the standoffs and reconnect each connector exactly per your photo.
- Test — Restore power, call for cooling, and confirm the diagnostic LED shows normal operation with no fault codes.
Signs You Need a Replacement
- Diagnostic LED is dark or stuck on a fault with no actual fault present.
- Compressor will not start despite a valid 24V cooling call.
- Nuisance lockouts or short cycling that clear when the board is bypassed.
- Visible burn marks, swollen capacitors, or corrosion 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