ICP Transformer for WAHL604A2 — 40VA 208/230V to 24V | Ships Today

Overview

This OEM control transformer (part number 1172028) steps down line voltage to the 24V control circuit that powers thermostats, relays, contactors, and the control board in your ICP/Tempstar/Heil model WAHL604A2 system. It accepts a 208/230V primary and delivers a 24V, 40VA secondary output. When a transformer fails, the entire low-voltage control system goes dead — the thermostat screen blanks, the contactor will not pull in, and the system will not start. Common causes of failure include a shorted secondary wire, an overloaded control circuit, or age-related winding breakdown.

Specifications

Compatibility

Direct-fit replacement for ICP, Tempstar, Heil, Comfortmaker, and other International Comfort Products family equipment using model WAHL604A2. The 40VA 208/230V-to-24V configuration is standard across many ICP air handlers and furnaces — always confirm your existing transformer's VA and voltage ratings before ordering.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter before touching any wiring.
2. Access — Remove the service panel to expose the control compartment.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the primary (line) and secondary (24V) leads, then unbolt the failed transformer from its mounting bracket.
5. Install — Mount the new transformer, match the primary taps to your supply voltage, and reconnect the secondary leads per your photo.
6. Test — Restore power and verify 24V across the secondary terminals and normal system startup.

Signs You Need a Replacement

• Blank thermostat with no 24V control power present.
• Contactor or relays will not energize even with a call for cooling/heating.
• Repeatedly blown low-voltage fuse or burnt smell at the transformer.
• No measurable voltage across the 24V secondary terminals.

Shipping & Returns

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