ICP 40VA Transformer for WFMR070A036B2 — 120V to 24V Control | Ships Today

Overview

This OEM 40VA control transformer (OEM 1177217) supplies the 24-volt control circuit for the ICP / Tempstar / Heil WFMR070A036B2 gas furnace. It steps the 120V line voltage down to 24V to power the thermostat, gas valve, control board, and relays. Rated at 40VA, it delivers enough capacity to drive the furnace controls plus an air-conditioning contactor on a shared low-voltage circuit. When a transformer fails — usually from a shorted thermostat wire, a stuck contactor, or simple age — the entire 24V system goes dead: no thermostat display, no call for heat or cool, and no response from the control board. A buzzing or hot transformer, or a blown low-voltage fuse that keeps recurring, points to a transformer at the end of its life or a downstream short.

Specifications

Compatibility

Direct OEM fit for the ICP WFMR070A036B2 furnace and its Tempstar, Heil, Comfortmaker, and Arcoaire equivalents. Confirm the 120V primary, 24V secondary, and 40VA rating match your existing transformer before installing.

Installation Guide

1. Safety First — Disconnect power at the switch and breaker and verify zero voltage with a multimeter.
2. Access — Remove the furnace control-compartment panel.
3. Document — Photograph the primary (120V) and secondary (24V) leads before disconnecting.
4. Remove — Disconnect the leads, unbolt the old transformer from its mount, and clear any blown inline fuse.
5. Install — Bolt the new transformer in place, reconnect the 120V primary and 24V secondary per your photo, and confirm no pinched wires.
6. Test — Restore power, measure ~24V across the secondary, and verify the thermostat powers up and the furnace responds to a call.

Signs You Need a Replacement

• Thermostat is blank and the furnace will not respond.
• No 24V output measured across the secondary terminals.
• Transformer buzzes, runs hot, or smells burnt.
• Low-voltage fuse blows repeatedly.

Shipping & Returns

Ships same day on orders placed before 3 PM CST. 30-day hassle-free returns. Backed by the National HVAC Parts fitment guarantee.