ICP Defrost Control Board for YJ042G — Heat Pump Timer Board | Ships Today

Overview

This OEM defrost control board (ICP part number 34332101) governs the defrost cycle on your ICP/Tempstar/Heil YJ042G heat pump. In heating mode, frost builds on the outdoor coil; the board tracks coil temperature and run time, then triggers a timed defrost that reverses refrigerant flow to clear the ice and protect efficiency. A failed board can leave the coil iced over, lock the unit in defrost, cause short-cycling, or stop heat output entirely. This 24V-controlled board sequences the reversing valve, compressor, and outdoor fan during the defrost cycle.

Specifications

Compatibility

Engineered as a direct OEM replacement for the ICP/Tempstar/Heil YJ042G heat pump and equivalent ICP-family units (Comfortmaker, Arcoaire). Confirm the part number on your existing board reads 34332101 before installing.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the outdoor unit's control-panel service cover.
3. Document — Photograph every wire and terminal on the old board before disconnecting.
4. Remove — Label and unplug each connector, release the standoff clips or screws, and lift out the failed board.
5. Install — Mount the new board and reconnect every wire exactly per your photo.
6. Test — Restore power and run a heating/defrost cycle to confirm correct operation.

Signs You Need a Replacement

• Outdoor coil ices over and never defrosts
• Unit stuck in defrost or blowing cold air in heat mode
• Compressor or reversing valve not energizing on schedule
• No 24V output to defrost components

Shipping & Returns

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