ICP 40VA Transformer for WFMR090B042B1 — 120V to 24V OEM Replacement | Ships Today

Overview

This genuine OEM control transformer (Part Number 1177217) steps line voltage down to the 24V control circuit on the ICP Tempstar Heil WFMR090B042B1 furnace. Rated at 40VA with a 120V primary and 24V secondary, it powers the thermostat, gas valve, control board, and relays. A failed transformer is one of the most common causes of a completely dead control circuit — no thermostat display, no call for heat, and no blower or igniter response. Transformers fail from a shorted secondary, age, or a wiring fault that overloads the winding.

Specifications

Compatibility

Built for the ICP Tempstar Heil WFMR090B042B1 furnace and other units in the WFMR090 series across ICP-family brands (Tempstar, Heil, Comfortmaker). Verify the 40VA / 120-24V rating and part number against your existing transformer.

Installation Guide

1. Safety First — Disconnect power at the switch and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the furnace control/service panel.
3. Document — Photograph the primary and secondary lead connections before disconnecting.
4. Remove — Disconnect the wiring and unbolt the old transformer from its bracket.
5. Install — Mount the new transformer and reconnect the 120V primary and 24V secondary leads exactly per your photo.
6. Test — Restore power and confirm 24V across the secondary and a normal call for heat.

Signs You Need a Replacement

• No 24V at the control board or thermostat
• Dead thermostat with no display or response
• Furnace won't start a heating cycle
• Burnt smell or scorched transformer housing

Shipping & Returns

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