ICP 40VA Transformer for WFAR100C042A1 — 120/24V OEM 1177217 | Ships Today

Overview

This genuine OEM 40VA control transformer (part number 1177217) powers the 24V control circuit on the ICP/Tempstar/Heil WFAR100C042A1 gas furnace. It steps the 120V line-voltage primary down to 24V on the secondary, supplying the thermostat, gas valve, ignition control board, and relays. When a transformer fails — usually from a shorted control wire, a stuck contactor, or simple age — the entire low-voltage system goes dead: no thermostat response, no call for heat, and no blower or ignition. A blown transformer is one of the most common no-heat causes on furnaces.

Specifications

Compatibility

Designed for the ICP WFAR100C042A1 furnace and widely shared across ICP-family equipment (Tempstar, Heil, Comfortmaker, Arcoaire) that uses a 40VA 120-to-24V control transformer. Confirm your existing primary voltage is 120V before installing.

Installation Guide

1. Safety First — Disconnect power at the switch and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the control-compartment service panel.
3. Document — Photograph all primary and secondary leads before disconnecting.
4. Remove — Unscrew the transformer mounting bracket and disconnect the wiring.
5. Install — Mount the new transformer and reconnect 120V primary and 24V secondary per your photo.
6. Test — Restore power, confirm 24V at the secondary, and verify a normal call for heat.

Signs You Need a Replacement

• No 24V at the secondary terminals (thermostat dead)
• Furnace completely unresponsive to a heat call
• Burnt smell or visible scorching on the transformer
• Repeated control-circuit fuse blowouts

Shipping & Returns

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