ICP Transformer for WFSR040A030A1 — 40VA 120/24V | Ships Today

Overview

This OEM ICP control transformer (part #1177217) steps down 120V line voltage to the 24V control voltage that powers your WFSR040A030A1 furnace's low-voltage circuit. Rated at 40VA, it feeds the thermostat, gas valve, control board, and relays. When a transformer fails, the entire control circuit dies: the thermostat goes blank, the burners and blower won't start, and no 24V is present at the board. A buzzing transformer, a blown low-voltage fuse, or a scorched smell indicates the original has shorted or overheated and must be replaced. This is a genuine OEM replacement matched to the exact electrical specs of the factory part.

Specifications

Compatibility

Directly fits ICP model WFSR040A030A1 and is shared across many Tempstar, Heil, and Comfortmaker furnaces and air handlers that use a 120V-to-24V 40VA control transformer. Confirm your old transformer's VA rating and voltage markings before installing.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter before touching any wiring.
2. Access — Remove the furnace or air handler service panel to expose the control compartment.
3. Document — Photograph all primary (120V) and secondary (24V) wire connections before disconnecting.
4. Remove — Disconnect the lead wires or terminals, then unbolt the transformer from its mounting bracket.
5. Install — Mount the new transformer and reconnect the primary and secondary leads exactly per your photo.
6. Test — Restore power and verify 24V across the secondary terminals and that the thermostat powers up.

Signs You Need a Replacement

• Thermostat screen is blank or completely dead
• No 24V reading at the control board or gas valve
• Audible buzzing or humming from the transformer
• Burnt smell or visible scorching on the transformer body

Shipping & Returns

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