OEM Carrier Control Transformer 40VA 120V to 24V for Model FX4DNF019L00AAAA

This is the OEM factory-replacement control transformer (part number HT01CN241) for the Carrier FX4DNF019L00AAAA fan coil air handler. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage control circuits. When this transformer fails, absolutely nothing in the control system responds — the thermostat goes blank, the unit won't call for heating or cooling, and you may measure zero volts at the secondary terminals. It is often the first component to check when the entire system appears dead despite line voltage being present.

• Specs: 40VA rated | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01CN241 | Factory-matched windings and enclosure for direct drop-in replacement
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances specified by Carrier engineering. Undersized or off-tolerance aftermarket transformers can overheat, trip their internal fuse repeatedly, or cause erratic low-voltage behavior that mimics other component failures.
• Install difficulty: 2/5 — Disconnect all power before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Photograph all low-voltage wiring before disconnecting terminals. Replace the transformer fuse if one is present and blown.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our climate-controlled warehouse.

Compatibility: Designed specifically for the Carrier FX4DNF019L00AAAA fan coil air handler. Confirm your existing transformer's VA rating and primary/secondary voltages on the unit data plate or transformer label before ordering. Our HVAC parts specialists are available to verify fitment — contact us before you buy if you have any questions. Order today and receive same-day shipping on all in-stock items.