ICP Integrated Furnace Control Board for RGS120LFAA0AAA — OEM 1183618 | Ships Today

Overview

This is the genuine OEM integrated furnace control board (kit 1183618) for the ICP/Tempstar/Heil RGS120LFAA0AAA gas furnace. The control board is the brain of the furnace — it manages the ignition sequence, monitors safety switches, sequences the inducer and blower motors, and times the gas valve and igniter. When this board fails, the furnace may fail to ignite, short-cycle, lock out, or run the blower continuously. Flashing diagnostic LED error codes on the board are a common symptom of a failing or failed control.

Specifications

Compatibility

Engineered as a direct-fit replacement for the ICP/Tempstar/Heil RGS120LFAA0AAA furnace. As a shared ICP-family part, it may also fit related Comfortmaker and Arcoaire models — always verify your existing board part number before ordering.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker. Verify zero voltage with a multimeter.
2. Access — Remove the furnace blower-compartment service panel.
3. Document — Photograph every wire and connector on the existing board before disconnecting anything.
4. Remove — Label and unplug each connector, remove the mounting screws/standoffs, and lift out the old board.
5. Install — Mount the new board on the same standoffs and reconnect every harness exactly per your photo.
6. Test — Restore power and run a full heat cycle; confirm the diagnostic LED shows a normal/steady status.

Signs You Need a Replacement

• Furnace will not ignite or fails to start a heat call
• Diagnostic LED flashing a fault/lockout error code
• Blower runs continuously or fails to start
• Visible burn marks, corrosion, or a swollen relay on the board

Shipping & Returns

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