ICP 40VA Transformer for WFML045A024B1 — 120V to 24V | Ships Today

Overview

This OEM 40VA control transformer (OEM 1177217) supplies the 24-volt control power for the ICP Tempstar/Heil WFML045A024B1 gas furnace. It steps 120V line voltage down to 24V to drive the thermostat, control board, gas valve, and relays. Rated at 40VA, it provides ample capacity for the furnace's control loads. When a transformer fails — usually from a control short or age — the entire 24V circuit goes dead: no thermostat response, no ignition sequence, and a completely unresponsive furnace.

Specifications

Compatibility

Engineered for the ICP Tempstar/Heil WFML045A024B1 and equivalent ICP-platform furnaces sold under Heil, Tempstar, Comfortmaker, and Arcoaire badges that use a 40VA 120/24V control transformer. Verify primary and secondary voltage against your existing transformer 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 control-compartment service panel.
3. Document — Photograph all primary (line) and secondary (24V) wire connections before disconnecting.
4. Remove — Disconnect the leads, remove the mounting screws, and lift out the failed transformer.
5. Install — Mount the new 40VA transformer, then reconnect the 120V primary and 24V secondary leads exactly per your photo.
6. Test — Restore power and confirm 24V at the secondary, then run a heat cycle to verify thermostat and control response.

Signs You Need a Replacement

• Thermostat is blank and furnace is completely unresponsive
• No measurable 24V at the transformer secondary
• Transformer is hot, buzzing, or shows burn marks
• Repeated blown low-voltage fuse traced to the transformer

Shipping & Returns

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