ICP 40VA Transformer for WPG4484090LKA1 — 208/230V to 24V | Ships Today

Overview

This is a genuine OEM 40VA control transformer (part number 1173691) with the matching 24V barrier (part number 1178431) for the ICP Tempstar Heil WPG4484090LKA1. The transformer steps the incoming 208/230V line voltage down to the 24V low-voltage power that runs the thermostat, control board, contactor coil, and gas valve. Without it, none of the low-voltage controls operate. The 24V barrier provides the required separation between line and low-voltage wiring for safe, code-compliant installation. A failed transformer is one of the most common causes of a completely dead control circuit — no thermostat display, no contactor pull-in, and no ignition sequence even though line power is present.

Specifications

Compatibility

Direct-fit OEM replacement for the ICP Tempstar Heil WPG4484090LKA1 packaged unit. As an ICP-built component, it also services equivalent Tempstar, Heil, Comfortmaker, and Arcoaire models that originally used the 1173691 transformer. Confirm primary voltage (208/230V), 40VA rating, and the part number on the existing unit before ordering.

Installation Guide

1. Safety First — Disconnect power at the breaker/disconnect and verify zero voltage with a multimeter on both line and 24V terminals.
2. Access — Remove the service panel to reach the control box.
3. Document — Photograph all primary and secondary wire connections and the barrier orientation.
4. Remove — Disconnect the line-voltage primary leads and the 24V secondary leads, then unbolt the transformer and barrier.
5. Install — Mount the new transformer and 24V barrier, then reconnect primary and secondary wiring exactly per your photos (match the correct primary tap for 208V or 230V).
6. Test — Restore power and verify 24V across the secondary terminals with a multimeter.

Signs You Need a Replacement

• No 24V output measured at the secondary terminals.
• Thermostat is blank and controls are completely dead with line power present.
• Visible burn marks, swelling, or a burnt smell on the transformer.
• Repeated blown low-voltage fuse caused by a shorted winding.

Shipping & Returns

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