ICP 40VA Transformer for WAHM482A1 — 208/230V to 24V OEM 1172028 | Ships Today

Overview

This ICP OEM step-down transformer (part number 1172028) reduces the 208/230V line voltage feeding the WAHM482A1 air handler to the 24V control voltage that drives the thermostat, relays, and low-voltage circuits. Rated at 40VA, it supplies the current the unit's control loads require. A failed transformer is a leading cause of a completely dead system: without 24V output the thermostat goes blank, relays and contactors won't energize, and nothing runs despite line power being present. These transformers typically fail from a shorted thermostat wire, a stuck contactor pulling excess current, or normal age and heat fatigue.

Specifications

Compatibility

Factory replacement transformer for the ICP/Tempstar/Heil WAHM482A1 air handler and related WAHM-series units originally equipped with part 1172028. Confirm your primary voltage tap (208 vs 230) matches your supply before energizing.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter.
2. Access — Remove the air handler control-box service panel.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the leads, unbolt the transformer from its bracket, and remove it.
5. Install — Mount the new 1172028 transformer, land the correct primary tap for your line voltage, and reconnect the 24V secondary leads per your photo.
6. Test — Restore power and verify 24V across the secondary and normal system operation.

Signs You Need a Replacement

• Blank thermostat and a completely unresponsive system.
• No 24V reading across the transformer secondary.
• Contactors or relays fail to energize on a call for heat or cool.
• Burn marks, melted housing, or a repeatedly blown control circuit.

Shipping & Returns

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