ICP Transformer for WAHM422A1 — 208/230V to 24V 40VA | Ships Today

Overview

This OEM control transformer (part number 1172028) supplies the 24V control power for your ICP WAHM422A1 air handler by stepping 208/230V line voltage down to 24V. Rated at 40VA, it feeds the thermostat, control board, relays, and contactor coils. A failed transformer kills all low-voltage control: the thermostat goes blank, the blower won't run, and the system appears completely dead despite line power being present. Buzzing, an open internal fuse link, or a charred secondary winding indicate failure — frequently triggered by a shorted thermostat wire or an overloaded control circuit.

Specifications

Compatibility

Direct OEM replacement for the ICP WAHM422A1 air handler and matching Tempstar, Heil, and Comfortmaker variants on the same 208/230V platform. Verify your existing transformer is 40VA, 208/230V primary to 24V secondary before installing.

Installation Guide

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

Signs You Need a Replacement

• No 24V control power — blank thermostat and dead blower
• Audible buzzing or humming from the transformer
• Burnt smell or scorched windings
• Control fuse blows again immediately after reset

Shipping & Returns

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