ICP Transformer for WFML045A024B3 — 40VA 120/24V | Ships Today

Overview

This OEM transformer (part #1177217) is the low-voltage power source for your ICP Tempstar Heil furnace. Rated at 40VA, it steps line voltage of 120V down to the 24V control signal that drives the thermostat, gas valve, igniter circuit, and blower relays. When a transformer fails — usually from a shorted control wire or a stuck contactor drawing excess current — the entire low-voltage system goes dead. A failed 40VA transformer is one of the most common causes of a completely unresponsive furnace.

Specifications

Compatibility

Directly fits the ICP Tempstar Heil WFML045A024B3 furnace and shares the same low-voltage platform as many ICP-family gas furnaces (Tempstar, Heil, Comfortmaker). Always confirm the 40VA rating and 120/24V configuration match your existing unit.

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 access panel.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the primary (line) and secondary (24V) leads, then unbolt the transformer from its mounting bracket.
5. Install — Mount the new transformer, reconnect the primary and secondary leads exactly per your photo.
6. Test — Restore power and confirm 24V at the secondary terminals and normal thermostat response.

Signs You Need a Replacement

• Furnace completely unresponsive — no blower, no ignition, blank thermostat
• No 24V reading at the secondary terminals
• Visible scorching, melted housing, or a burnt smell at the transformer
• Repeated control-circuit fuse failures

Shipping & Returns

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