ICP Transformer for WFML110C066B3 — 40VA 120/24V | Ships Today

Overview

This genuine OEM control transformer (part number 1177217) is rated 40VA 120V-24V and fits the ICP Tempstar Heil WFML110C066B3 gas furnace. It steps down 120V line voltage to the 24V control voltage that powers the thermostat, gas valve, ignition control, and relay circuit. The 40VA rating supplies the current the entire low-voltage control side requires. A failed transformer leaves the furnace dead on the control side — no thermostat display, no call for heat — and frequently blows the control board's low-voltage fuse. Buzzing, overheating, or a scorched housing all indicate the transformer has failed and must be replaced.

Specifications

Compatibility

Direct OEM fit for the ICP Tempstar Heil WFML110C066B3 furnace and compatible across ICP-family gas furnaces using a 40VA 120V-to-24V control transformer. Confirm your existing transformer is rated 120V primary / 24V secondary at 40VA before installing.

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 service panel.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the 120V primary and 24V secondary leads, then unbolt the transformer from its bracket.
5. Install — Mount the new transformer and reconnect primary and secondary leads exactly per your photo.
6. Test — Restore power, confirm 24V across the secondary, and verify the furnace responds to a call for heat.

Signs You Need a Replacement

• Furnace fully unresponsive — no thermostat power or display
• Repeatedly blown low-voltage control fuse
• Buzzing or humming from the transformer
• Burnt smell, discoloration, or melted housing

Shipping & Returns

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