ICP 40VA Transformer for WFML090B042A1 — 120/24V Control | Ships Today

Overview

This genuine OEM control transformer (ICP part number 1176944) steps the 120V line voltage down to the 24V control power that runs your furnace circuit board, thermostat, gas valve, and igniter circuit on the ICP / Heil / Tempstar WFML090B042A1. A failed transformer is one of the most common causes of a completely dead furnace: no thermostat display, no blower, no ignition sequence. Rated at 40VA, it supplies enough current for the full control load while protecting downstream components. If you have measured 120V at the primary but no 24V at the secondary, the transformer has failed and should be replaced.

Specifications

Compatibility

Built for the ICP / Heil / Tempstar WFML090B042A1 gas furnace and other ICP-family furnaces using a 120/24V 40VA control transformer. Confirm primary voltage and VA rating against your existing unit before ordering.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker; verify zero voltage at the transformer leads with a multimeter.
2. Access — Remove the furnace control-compartment service panel.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the leads, unscrew the transformer from its mounting bracket, and remove it.
5. Install — Mount the new transformer, reconnect the 120V primary and 24V secondary leads exactly per your photo.
6. Test — Restore power and confirm 24V at the secondary and a normal thermostat call.

Signs You Need a Replacement

• Furnace completely dead — no thermostat power, no blower, no ignition
• 120V present at primary but no 24V at secondary
• Visible burn marks, swelling, or a burnt smell from the transformer
• Blown low-voltage fuse that recurs immediately on a call for heat

Shipping & Returns

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