ICP 40VA Transformer for WFAR100C048B2 — 120V to 24V | Ships Today

Overview

This OEM control transformer (part #1177217, TRANSFORMER 40VA 120-24V) supplies the 24-volt control power for the ICP/Heil/Tempstar WFAR100C048B2. It steps the 120V line voltage down to the 24VAC that operates the thermostat, control board, gas valve, relays, and contactor circuits. Rated at 40VA, it provides enough capacity to drive the full low-voltage control load. When a transformer fails, the entire control side of the system goes dead even though line voltage is present — the thermostat goes blank, nothing energizes, and the system will not start. Transformers commonly fail from a shorted control wire, a seized component drawing excess current, or simple age-related winding breakdown. This OEM unit matches the factory primary/secondary voltages and mounting so it drops straight in.

Specifications

Compatibility

Designed for the ICP/Heil/Tempstar WFAR100C048B2 and matching WFAR-series units that use a 40VA 120-to-24V control transformer. Verify your primary is 120V before installing.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter.
2. Access — Remove the control compartment service panel.
3. Document — Photograph the primary and secondary leads before disconnecting.
4. Remove — Unfasten the transformer mounting and disconnect the wire leads.
5. Install — Mount the new transformer, land the 120V primary and 24V secondary leads per your photo, and check for any shorted control wiring first.
6. Test — Restore power and confirm 24VAC at the secondary and a live thermostat.

Signs You Need a Replacement

• Thermostat display is blank with line power present
• No 24V output measured at the secondary
• System will not energize any control component
• Transformer is hot, buzzing, or smells burnt

Shipping & Returns

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