ICP Defrost Control Board for YC042G — 24V Heat Pump | Ships Today

Overview

This is the genuine OEM defrost control board (part number 34332100) for the ICP / Tempstar / Heil YC042G heat pump. The defrost board manages the outdoor unit in heating mode — it watches the defrost thermostat and accumulated run time, then commands the reversing valve, brings on auxiliary heat, and stops the outdoor fan to clear frost from the coil. A 24V control circuit powers its relays and timing logic. A failed board can let the heat pump ice over, skip defrost, short cycle, or stop responding to the thermostat entirely.

Specifications

Compatibility

Direct-fit replacement for the ICP, Tempstar, and Heil YC042G heat pump and other outdoor units using OEM defrost board 34332100. Verify the board part number and connector layout against your existing board before installing.

Installation Guide

1. Safety First — Disconnect power at the outdoor disconnect and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the condensing unit electrical/service panel.
3. Document — Photograph every plug, terminal, and wire color on the board before disconnecting.
4. Remove — Unplug the harnesses, release the board standoffs or screws, and lift out the old board.
5. Install — Mount the new board and reconnect each harness to the matching terminal per your photo.
6. Test — Restore power, confirm the board powers up, and verify a normal defrost cycle and reversing valve operation.

Signs You Need a Replacement

• Outdoor coil ices over and never enters defrost.
• Heat pump short cycles or won't switch modes.
• Reversing valve or auxiliary heat won't energize on a call.
• Outdoor unit unresponsive despite correct thermostat signals.

Shipping & Returns

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