ICP 40VA Transformer for WUGC105CG01 — 120V to 24V with SPDT Relay | Ships Today

Overview

This OEM transformer assembly powers the 24V control circuit on the ICP/Heil/Tempstar WUGC105CG01 gas furnace. It steps 120V line voltage down to 24V at 40VA, supplying the thermostat, gas valve, ignition control, and relays. The kit pairs the OEM transformer-relay receptacle (part 97298, TRANS RELAY RECEP 120>25 40VA) with a 24V SPDT switching relay (part 92840). When this transformer fails, the entire low-voltage control system loses power — the thermostat goes dark, the gas valve will not open, and the furnace will not start. A buzzing transformer, scorched windings, or repeatedly tripped fuses are classic signs of a failing 40VA transformer.

Specifications

Compatibility

Engineered as a direct OEM fit for the ICP/Heil/Tempstar WUGC105CG01 gas furnace and shared platform models that use the 40VA 120V-to-24V control transformer. Always confirm your model number before ordering.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the furnace control/blower compartment service panel.
3. Document — Photograph all primary (120V) and secondary (24V) wire connections before disconnecting.
4. Remove — Disconnect the wiring leads, unbolt the failed transformer from the control bracket, and detach the relay from its receptacle.
5. Install — Mount the new transformer and relay, then reconnect each lead exactly per your photo.
6. Test — Restore power and confirm 24V across the secondary terminals and a normal heat call.

Signs You Need a Replacement

• Thermostat display is blank and furnace is unresponsive
• Audible buzzing or humming from the transformer
• Blown low-voltage fuse on the control board
• Burnt smell or visibly scorched transformer windings

Shipping & Returns

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