OEM Carrier Transformer 40VA 120V/24V for Model FA4ANC030010AGAA

This OEM replacement transformer (part number HT01CN236) is the factory-specified 40VA step-down transformer for the Carrier FA4ANC030010AGAA air handler. The transformer converts 120V line voltage down to the 24V signal voltage that powers your control board, thermostat, and all low-voltage control circuits. When this transformer fails — often due to a short in the control circuit or wiring fault — absolutely nothing in the system responds: the thermostat goes blank, the air handler won't call for heating or cooling, and the system appears completely dead despite having line power.

• Specs: 40VA transformer | Primary: 120V AC | Secondary: 24V AC | Factory OEM part number HT01CN236 | Direct drop-in replacement with original mounting footprint and wire leads
• OEM vs Generic: This is the factory-matched OEM unit, wound to exact VA and voltage tolerances. Generic transformers can deliver inconsistent secondary voltage, causing erratic thermostat behavior, nuisance lockouts, and premature control board failure — false economy on a critical component.
• Install difficulty: 2/5 — Turn off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, wire stripper, multimeter (confirm 0V before touching wires). Photograph all wire connections before disconnecting the old transformer. Note: always check for a shorted control wire or stuck contactor coil before installing the new transformer, or the replacement will fail immediately.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock and ships same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier FA4ANC030010AGAA air handler. Verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering to ensure fitment. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you order — contact us today and we'll confirm the correct part for your unit.