OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
This OEM replacement transformer (part number HT01CN241) is the factory-specified control circuit transformer for the Carrier FX4DNF037T10ABAA fan coil air handler. The transformer steps line voltage down from 120V to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When this component fails, the entire control circuit goes dead: the thermostat loses power, the system won't respond to calls for heating or cooling, and nothing turns on. A failed transformer is often mistaken for a bad thermostat or control board, so always verify 24V output at the secondary terminals before replacing other components.
Compatibility: Designed for the Carrier FX4DNF037T10ABAA fan coil air handler. Verify primary voltage and VA rating on your unit's data plate before ordering. If you're unsure of fitment, our parts specialists confirm compatibility before you buy — no guesswork.