ICP Transformer for WAHT424B1 — 40VA 208/230V to 24V | Ships Today

Overview

This is the OEM 40VA control transformer (part number 1172028) for the ICP WAHT424B1 air handler. It steps down 208/230V line voltage to the 24V low-voltage power that runs the thermostat, control board, contactor coil, and relays. A failed transformer kills the entire 24V control circuit — the thermostat blanks out, the blower and heat/cool won't energize, and the unit appears dead despite line voltage being present. Buzzing, overheating, or a scorched/burned body indicates failure, typically from a shorted control wire or a stuck contactor coil pulling excess current.

Specifications

Compatibility

Engineered as a direct OEM fit for the ICP WAHT424B1 air handler and other Tempstar, Heil, and Comfortmaker fan coil units that use part 1172028. Confirm the part number on your existing transformer before ordering.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter at the line and load terminals.
2. Access — Remove the air handler 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 bracket.
5. Install — Mount the new transformer, matching the 208/230V primary taps and 24V secondary leads per your photo.
6. Test — Restore power and confirm 24V at the secondary terminals and a responsive thermostat.

Signs You Need a Replacement

• Thermostat is blank or dead with no 24V control power
• System will not start in heating or cooling despite line voltage present
• Transformer is buzzing, hot to the touch, or visibly burned
• No 24V output measured at the secondary leads

Shipping & Returns

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