Tempstar ComfortAlert Control Board for T4A424GKD200 — Compressor Diagnostics | Ships Today

Overview

This is a genuine OEM ComfortAlert control board (part number 1177402) for the Tempstar T4A424GKD200 air conditioning condensing unit. The ComfortAlert diagnostic module continuously monitors compressor and electrical operation, using a flashing fault LED to report conditions such as long run cycles, low or high voltage, locked rotor, open circuit, missing phase, and low pressure. It protects the compressor by detecting abnormal operating conditions early and giving technicians a clear diagnostic code instead of guesswork. When this board fails, the outdoor unit may not respond to cooling calls, the diagnostic LED may go dark or flash erratically, the compressor may short cycle, or fault codes may persist even after the underlying issue is resolved. Replacing the board with the correct OEM part restores both normal operation and the unit's built-in compressor protection.

Specifications

Compatibility

This control board is the factory-specified part for the Tempstar T4A424GKD200 condensing unit and fits other ICP-family (Heil, Comfortmaker, Arcoaire) units that use ComfortAlert part 1177402. Always confirm the part number printed on your existing board before ordering, as ComfortAlert modules vary by application.

Installation Guide

1. Safety First — Disconnect power at the outdoor disconnect and breaker, then verify zero voltage with a multimeter before touching the board.
2. Access — Remove the condensing unit's electrical access panel.
3. Document — Photograph every wire and connector on the board before disconnecting anything.
4. Remove — Disconnect the low-voltage and sensing leads, release the mounting standoffs or screws, and lift out the old board.
5. Install — Mount the new board, reconnect each lead to the matching terminal per your photo, and confirm all connectors are fully seated.
6. Test — Restore power, call for cooling, and verify the diagnostic LED shows a normal status and the compressor and fan operate correctly.

Signs You Need a Replacement

• Outdoor unit does not respond to cooling calls despite proper line and control voltage.
• Diagnostic LED is dark, flashes erratically, or shows codes that persist after the fault is cleared.
• Compressor short cycles or fails to start with no other identifiable cause.
• Visible burn marks, swollen components, 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.