ICP Defrost Control Board Kit for RHS181H0CA0AAAA — Heat Pump Control | Ships Today

Overview

This OEM control board kit (part 1183618) is the brain of the ICP / Tempstar / Heil RHS181H0CA0AAAA heat pump. The defrost control board monitors outdoor coil temperature and run time, then commands the reversing valve and condenser fan through a defrost cycle to clear frost from the outdoor coil in heating mode. It also coordinates the compressor contactor and 24V control logic. A failed board causes erratic operation, a coil that ices over, a unit stuck in defrost, or no outdoor unit response at all. The kit ships with the OEM board and mounting hardware for a direct replacement.

Specifications

Compatibility

Built for the ICP-family RHS181H0CA0AAAA 1.5-ton heat pump and equivalent Tempstar, Heil, Comfortmaker, and Arcoaire units. Match the OEM kit number against your existing board before ordering, as defrost timing and pin layouts vary by chassis.

Installation Guide

1. Safety First — Disconnect power at the outdoor disconnect and verify zero voltage with a multimeter.
2. Access — Remove the service panel to reach the control box and mounted board.
3. Document — Photograph every connector, the defrost timing jumper position, and all wire colors before disconnecting.
4. Remove — Unplug the connectors, release the board standoffs or screws, and lift out the old board.
5. Install — Mount the new board, set the defrost timing jumper to match the original, and reseat every connector per your photo.
6. Test — Restore power, run a heating cycle, and confirm the board initiates and terminates defrost correctly.

Signs You Need a Replacement

• Outdoor coil ices over and won't defrost
• Unit stuck running defrost continuously
• No response from the outdoor unit on a heat call
• Erratic compressor or reversing-valve switching

Shipping & Returns

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