ICP 24V Transformer for RGS243HRFA0AAAA — 40VA Control Power | Ships Today

Overview

This OEM 24-volt control transformer supplies the low-voltage power that drives the relays, contactor coil, and control logic in the ICP RGS243HRFA0AAAA system. Rated at 40VA with a 24V secondary, it converts incoming line voltage down to the 24VAC required by the unit's DPDT relay (OEM 1183814 / T92S11A22-24) and DPST relay (OEM 1178205 / T92P7A22-24). When the transformer fails, the entire control circuit goes dead — the thermostat loses power, relays stop pulling in, and the system will not start even though high-voltage power is present. A buzzing transformer, a blown low-voltage fuse, or 0 volts across the secondary terminals are classic signs of a unit at the end of its life.

Specifications

Compatibility

Engineered as a direct-fit replacement for the ICP/Tempstar/Heil RGS243HRFA0AAAA and closely related RGS243 series units. Supplies control voltage to the 24V DPDT and DPST relays used in this platform.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter.
2. Access — Remove the control panel cover.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the line-voltage primary and 24V secondary leads, then unbolt the old transformer from the bracket.
5. Install — Mount the new transformer, reconnect primary and secondary leads exactly per your photo.
6. Test — Restore power and confirm 24VAC across the secondary terminals.

Signs You Need a Replacement

• No 24V control power and a dead thermostat display
• Repeatedly blown low-voltage fuse or tripped control circuit
• Audible buzzing or overheating at the transformer body
• Relays and contactor fail to energize despite a call for cooling/heating

Shipping & Returns

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