ICP Defrost Control Board for YC018G – Heat Pump | Ships Today

Overview

This genuine OEM defrost control board (part number 34332100) is the brain of the defrost cycle on the ICP/Tempstar/Heil YC018G heat pump. The board monitors the defrost thermostat and a timed interval, then initiates a defrost cycle to melt frost off the outdoor coil — reversing the valve, stopping the outdoor fan, and energizing auxiliary heat as needed. When this board fails, the outdoor coil ices over and heating capacity collapses, or the unit defrosts constantly and wastes energy. A failed board is a common cause of a frozen outdoor unit, a heat pump that won't switch to defrost, or erratic relay operation.

Specifications

Compatibility

Direct-fit replacement for the ICP/Tempstar/Heil YC018G heat pump and related models using board 34332100. Confirm the defrost timing pin settings on your old board and match them on the new board before powering up.

Installation Guide

1. Safety First – Disconnect power at the breaker and disconnect, and verify zero voltage with a multimeter.
2. Access – Remove the condenser control-box service panel.
3. Document – Photograph every connector and the defrost-timing jumper position before disconnecting.
4. Remove – Unplug the harness connectors, release the board standoffs/screws, and remove the old board.
5. Install – Mount the new board, set the timing pin to match the original, and reconnect all harnesses per your photo.
6. Test – Restore power, force or wait for a defrost cycle, and confirm proper changeover and fan operation.

Signs You Need a Replacement

• Outdoor coil freezes over in heating mode.
• Heat pump never enters defrost, or defrosts constantly.
• Relays don't click or sequence correctly.
• Visible burn marks 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.