ICP 40VA Transformer for WFML070A024B1 — 120V to 24V Control | Ships Today

Overview

This OEM 40VA control transformer (OEM 1177217) steps the furnace's 120V line voltage down to the 24V control voltage that powers the thermostat, gas valve, control board relays, and contactor circuits on the ICP / Heil / Tempstar WFML070A024B1. Rated at 40 volt-amps, it supplies enough secondary current for the full furnace control load. When a transformer fails — usually from a shorted secondary, an overloaded control circuit, or age — the furnace goes completely dead: no thermostat display, no blower, no ignition. A blown transformer is frequently caused by a downstream short, so inspect the 24V wiring before installing the replacement.

Specifications

Compatibility

Engineered as the exact-fit 40VA 120-to-24V transformer for the ICP family WFML070A024B1 gas furnace and its Heil, Tempstar, and Comfortmaker badge-equivalents. Verify your primary voltage is 120V and the VA rating matches before ordering.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker, and verify zero voltage with a multimeter.
2. Access — Remove the furnace control/blower service panel.
3. Document — Photo all primary (120V) and secondary (24V) lead connections before disconnecting.
4. Remove — Disconnect the leads, 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 confirm 24V at the secondary and normal thermostat/control operation.

Signs You Need a Replacement

• Furnace completely dead — no thermostat display or control response.
• No 24V reading at the secondary terminals with 120V present on the primary.
• Burnt smell, scorched casing, or visibly melted windings.
• Repeatedly blown low-voltage fuse on the control board.

Shipping & Returns

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