ICP Defrost Control Board for YA100FA1 — Heat Pump Defrost | Ships Today

Overview

This OEM defrost control board (part 1052757) is the brain of the defrost cycle on your ICP Heil Tempstar YA100FA1 heat pump. It monitors coil temperature and run time, then initiates and terminates the defrost cycle, energizes the reversing valve, and switches the outdoor fan as needed to clear frost from the outdoor coil in heating mode. A failed defrost board leaves the outdoor coil iced over, kills heating capacity, lets the unit run continuously without defrosting, or locks the compressor out entirely. Because the board also coordinates the reversing valve and fan, a fault here can mimic a wide range of other failures, so it is a high-value part to have on hand.

Specifications

Compatibility

Direct OEM replacement for the ICP / Heil / Tempstar / Comfortmaker YA100FA1 heat pump and related models built on the same defrost control platform. Confirm the board part number printed on your existing board before ordering.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the control-box service panel from the condensing unit.
3. Document — Photograph every connector and wire position on the board before disconnecting.
4. Remove — Unplug the wiring harnesses and defrost sensor, then unclip or unscrew the old board from its standoffs.
5. Install — Mount the new board, reconnect each harness and the defrost sensor exactly per your photo, and verify dip-switch/timer settings match the original.
6. Test — Restore power and confirm normal heat/cool operation and a proper forced defrost cycle.

Signs You Need a Replacement

• Outdoor coil ices up and never clears in heating mode
• Unit won't switch into or out of defrost
• Reversing valve or outdoor fan not responding
• No heat-pump operation despite good 24V power

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.