ICP Transformer for WFML110C048B3 — 40VA 120/24V | Ships Today

Overview

This OEM 40VA control transformer (part #1177217) is a direct replacement for ICP Tempstar Heil furnace WFML110C048B3. It converts the 120V incoming line voltage to the 24V control voltage that powers the thermostat, gas valve, igniter circuit, and control board. When this transformer fails, the entire low-voltage side goes dead — the thermostat blanks, the furnace ignores calls for heat, and any inline low-voltage fuse may blow repeatedly. Rated at 40VA, it delivers the control current the WFML110C048B3 board and accessories require. Common failure signs include a humming transformer, a scorched smell at the control box, or a transformer that no longer reads 24V on the secondary.

Specifications

Compatibility

Built for ICP Tempstar Heil model WFML110C048B3 and shared across ICP-family gas furnaces and air handlers (Comfortmaker, Arcoaire, KeepRite) using the same 40VA 120/24V control transformer. Confirm the VA rating and voltage stamped on your existing unit 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/burner service panel.
3. Document — Photograph all 120V primary and 24V secondary connections before disconnecting.
4. Remove — Disconnect the leads and unbolt the transformer from its bracket.
5. Install — Mount the new transformer and reconnect the primary and secondary leads exactly per your photo.
6. Test — Restore power, confirm 24V across the secondary, and verify a normal heating cycle.

Signs You Need a Replacement

• Blank or dead thermostat
• Furnace unresponsive to a call for heat
• Recurring blown low-voltage fuse
• Buzzing, humming, or burnt smell from the transformer

Shipping & Returns

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