ICP 40VA Transformer for WFMR045A024B1 — 120V to 24V | Ships Today

Overview

This OEM control transformer (part #1177217, TRANSFORMER 40VA 120-24V) steps your incoming 120V line voltage down to the 24V control voltage that powers the thermostat, gas valve, igniter circuit, and control board in the ICP/Tempstar/Heil WFMR045A024B1 gas furnace. Rated at 40VA, it supplies enough current for the full low-voltage control load. When a transformer fails—often from a control short or age—the thermostat goes dead, the furnace won't fire, and you may smell burnt insulation or see a tripped control fuse. Installing a fresh OEM transformer restores reliable 24V control power.

Specifications

Compatibility

Designed for the ICP WFMR045A024B1 furnace and used across many Tempstar, Heil, Comfortmaker, and Day & Night models with 120V primary control circuits. Verify your existing transformer is a 40VA, 120V-to-24V unit before installing.

Installation Guide

1. Safety First — Disconnect power at the switch and breaker, then confirm zero voltage with a multimeter.
2. Access — Remove the furnace control/junction access panel.
3. Document — Photograph every primary and secondary lead before disconnecting.
4. Remove — Disconnect the line and low-voltage wires and unbolt the old transformer from the mounting plate.
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 working thermostat call.

Signs You Need a Replacement

• Thermostat display is blank with power confirmed at the furnace
• No 24V reading at the secondary terminals
• Repeated blown control fuses or burnt-smell from the control area
• Furnace ignores all thermostat calls

Shipping & Returns

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