ICP Control Transformer for WFML070A036B3 — 40VA 120/24V | Ships Today

Overview

This OEM control transformer (part #1177217) supplies the 24-volt control power that runs your ICP Tempstar Heil furnace's thermostat, gas valve, ignition control, and relays. It steps a 120V line-voltage primary down to a 24V secondary and is rated at 40VA, enough to drive the full low-voltage control circuit on the WFML070A036B3. When a transformer fails — usually from a shorted thermostat wire, a stuck contactor, or simple age — the entire control circuit goes dead: no display, no call for heat, and no 24V at the R and C terminals. A buzzing or visibly burnt transformer is a sure sign of failure.

Specifications

Compatibility

Engineered for the ICP Tempstar Heil WFML070A036B3 furnace and shared across many ICP-family gas furnaces and air handlers using a 40VA 120/24V control transformer. Verify your existing transformer's VA and voltage ratings 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/blower service panel.
3. Document — Photograph all primary (line) and secondary (24V) wire connections before disconnecting.
4. Remove — Disconnect the primary and secondary leads, then unbolt the old transformer from its mounting bracket.
5. Install — Mount the new transformer, reconnect primary to line voltage and secondary to the R/C control terminals per your photo.
6. Test — Restore power and confirm 24V across the secondary terminals and a normal call for heat.

Signs You Need a Replacement

• No 24V control power — blank thermostat, no response to a heat call.
• Audible humming or buzzing from the transformer.
• Visible scorching, melted housing, or a burnt-electrical smell.
• Repeatedly blown low-voltage fuse traced back to the transformer.

Shipping & Returns

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