ICP 24V Transformer for WAMA36004AT2 — 40VA Control Transformer | Ships Today

Overview

This OEM 24V control transformer (part 202300900212) is the factory replacement for the ICP/Tempstar/Heil WAMA36004AT2. The transformer steps incoming line voltage (120/208/240V depending on primary tap) down to the 24-volt control signal that powers the thermostat, contactor coil, control board, and safety circuit. Rated at 40VA, it supplies enough current to energize the system's low-voltage controls. When a transformer fails — often from a shorted thermostat wire or a stuck contactor drawing excess current — the entire system goes dead: no thermostat display, no call for cooling or heating, and frequently a blown fuse on the control board.

Specifications

Compatibility

Direct OEM fit for the ICP/Tempstar/Heil WAMA36004AT2 and shared across many ICP-family units using a 40VA control circuit. Confirm the VA rating and primary voltage tap on your existing transformer before ordering.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter.
2. Access — Remove the service panel to reach the control compartment.
3. Document — Photograph the primary (line) and secondary (24V) wire connections before disconnecting.
4. Remove — Disconnect the leads, unbolt the transformer from its mounting bracket, and remove it.
5. Install — Mount the new transformer, matching the primary tap to your supply voltage, and reconnect all leads per your photo.
6. Test — Restore power and confirm 24 VAC at the secondary and a working thermostat display.

Signs You Need a Replacement

• No power to the thermostat and no system response to a call
• Repeatedly blown low-voltage fuses on the control board
• Burning smell or visible scorching on the transformer body
• No measurable 24 VAC across the secondary terminals

Shipping & Returns

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