ICP Transformer for WAHM304A1 — 40VA 208/230V to 24V | Ships Today

Overview

This OEM transformer (part number 1172028) is the 24-volt control power supply for your ICP WAHM304A1 air handler. It is a 40VA step-down transformer with a dual-tap 208/230V primary winding and a 24V secondary that powers the thermostat, control board, and low-voltage relays. When a transformer fails, the entire low-voltage control circuit goes dead — the thermostat screen blanks, the blower and relays will not energize, and the system appears completely unresponsive even though line voltage is present. A buzzing transformer, scorched windings, or a tripped low-voltage fuse are all signs the original unit has shorted or burned out.

Specifications

Compatibility

Designed as a direct OEM replacement for the ICP WAHM304A1 air handler. ICP manufactures equipment sold under the Tempstar, Heil, Comfortmaker, and Arcoaire brands, so this 40VA transformer also services many comparable WAHM-series fan coils that share the same 208/230V-to-24V control architecture. Always confirm the 1172028 part number against your existing transformer before installing.

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 air handler service panel to expose the control board and transformer.
3. Document — Photograph all primary and secondary wire connections before disconnecting anything.
4. Remove — Disconnect the line-voltage primary leads and the 24V secondary leads, then unbolt the transformer from its mounting bracket.
5. Install — Mount the new transformer, wire the correct primary tap for your supply voltage (208V or 230V), and reconnect the 24V secondary per your photos.
6. Test — Restore power and confirm 24VAC across the secondary terminals and normal control operation.

Signs You Need a Replacement

• Thermostat is blank or dead while line voltage is confirmed present.
• Blower, relays, or contactor will not energize on a call for heat or cool.
• Audible buzzing or humming from the transformer, or a burnt-electrical smell.
• Repeatedly blown low-voltage fuse or no measurable 24VAC at the secondary.

Shipping & Returns

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