ICP 40VA Transformer for WFMR110C048B3 — 120V to 24V | Ships Today

Overview

This OEM 40VA control transformer (part 1177217) steps the 120V line voltage down to 24V to power the low-voltage control circuit of the ICP Tempstar Heil WFMR110C048B3 furnace. The 24V output drives the thermostat, gas valve, control board, and inducer relay. When a transformer fails — usually from an overload, short, or age — the furnace goes completely dead at the thermostat: no display, no call for heat, and no control response. A blown transformer is a frequent cause of a no-power control circuit and is often paired with a shorted gas valve or pinched low-voltage wire.

Specifications

Compatibility

Direct OEM fit for the ICP Tempstar Heil WFMR110C048B3 and related ICP family equipment (Comfortmaker, Heil, Tempstar) using a 40VA 120-24V control transformer. Verify primary voltage and VA rating against your unit before ordering.

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/service panel.
3. Document — Photograph the primary (line) and secondary (24V) wiring before disconnecting.
4. Remove — Disconnect the leads, remove the transformer mounting screws, and lift out the old unit.
5. Install — Mount the new transformer and reconnect the 120V primary and 24V secondary leads per your photo.
6. Test — Restore power, confirm 24V at the secondary with a meter, and verify the thermostat and control board power up.

Signs You Need a Replacement

• Thermostat is blank and the furnace is dead at the control circuit.
• No 24V measured across the transformer secondary.
• Burnt smell, scorched casing, or visibly melted windings.
• Repeated blown fuses or no response to a heat call.

Shipping & Returns

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