ICP Transformer for WAHM304A2 — 40VA 208/230V to 24V | Ships Today

Overview

This is a genuine OEM 40VA control transformer (part number 1172028) for the ICP/Heil/Tempstar WAHM304A2 air handler. The transformer steps the incoming 208/230V line voltage down to the 24V control voltage that powers the thermostat, fan-coil control board, and relays. When it fails, the low-voltage control circuit loses power and the system will not respond. Typical symptoms include a dead thermostat, repeatedly blown low-voltage fuses, or a burnt-coil odor from an overloaded transformer. The 40VA rating supplies the control loads on this model with margin to spare.

Specifications

Compatibility

Direct OEM fit for the ICP/Heil/Tempstar WAHM304A2 air handler and other WAHM-series fan coils using the 208/230V to 24V control circuit. Confirm your existing transformer is rated 40VA with matching primary and secondary taps 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 box.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Label and disconnect the line-voltage primary leads and the 24V secondary leads, then unbolt the failed transformer from its bracket.
5. Install — Mount the new transformer, reconnect the primary taps to the correct line voltage (208 or 230) and reconnect the 24V secondary leads per your photo.
6. Test — Restore power and verify 24V across the secondary and a responsive thermostat.

Signs You Need a Replacement

• Blank or unresponsive thermostat
• Repeatedly blown 3A or 5A low-voltage fuses
• No 24V output measured across the secondary
• Burning smell or visibly scorched transformer housing

Shipping & Returns

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