ICP Transformer for WFMR110C066B1 — 40VA 120/24V | Ships Today

Overview

This is a genuine OEM 40VA control transformer (part number 1177217) for the ICP / Tempstar / Heil model WFMR110C066B1. The transformer steps down the 120V line voltage to the 24V control voltage required to power the furnace control board, gas valve, thermostat, and low-voltage accessories. When a transformer fails, the entire low-voltage control circuit goes dead — the thermostat screen goes blank, the blower and ignition never energize, and the unit appears completely unresponsive even though line power is present. A 40VA rating provides the current capacity needed to drive the board and a typical R-W-Y-G control load.

Specifications

Compatibility

Engineered as a direct OEM replacement for ICP, Tempstar, Heil, Comfortmaker, and related family furnaces using model WFMR110C066B1. Always confirm the 120V primary and 24V secondary match your existing transformer before installing.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker, then verify zero voltage with a multimeter at the transformer leads.
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 transformer from its mounting bracket.
5. Install — Mount the new transformer, reconnect the 120V primary and 24V secondary leads exactly per your photo.
6. Test — Restore power and confirm 24V across the secondary and a normal thermostat call.

Signs You Need a Replacement

• Blank thermostat and no 24V control power anywhere in the system
• Furnace completely dead despite confirmed 120V line voltage
• Burnt smell or visibly scorched transformer housing
• Repeatedly blown low-voltage fuse or tripped board fuse

Shipping & Returns

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