ICP 40VA Transformer for WAHM484B1 — 208/230V to 24V | Ships Today

Overview

This OEM control transformer (part number 1172028) steps down line voltage to the 24-volt power your HVAC control circuit needs. With a 208/230V primary and a 24V secondary rated at 40VA, it powers the thermostat, control board, contactor coil, and other low-voltage components in the ICP WAHM484B1 air handler. When a transformer fails, the entire 24V control circuit goes dead — the thermostat screen goes blank, the blower won't energize, and no calls for heat or cool reach the equipment. Transformers commonly fail from a shorted low-voltage wire, a seized contactor coil, or simple age-related winding breakdown.

Specifications

Compatibility

Designed as the factory replacement for the ICP WAHM484B1 fan coil / air handler. The 1172028 transformer is also shared across many Tempstar, Heil, and Comfortmaker air handlers and furnaces that use a 208/230V-to-24V 40VA control transformer. Always confirm your unit's primary voltage and VA rating 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 anything.
4. Remove — Disconnect the line-voltage primary leads and the 24V secondary leads, then unbolt the failed transformer from the control box.
5. Install — Mount the new 1172028, then reconnect the primary and secondary wiring exactly as photographed.
6. Test — Restore power and confirm 24V across the secondary; verify the thermostat powers up and the system responds to a call.

Signs You Need a Replacement

• Blank thermostat and a completely dead 24V control circuit.
• No reading (or no 24V) across the transformer secondary terminals.
• Repeated blown low-voltage fuses or a visibly burnt/overheated transformer.
• System won't start even though line voltage is present at the unit.

Shipping & Returns

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