OEM Carrier 40VA Control Transformer for Model FX4DNF031T08ABAA (HT01CN241)

This OEM replacement transformer (part number HT01CN241) is the factory-specified 24V control circuit transformer for the Carrier FX4DNF031T08ABAA fan coil air handler. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, and all low-voltage safety controls. When this component fails, the entire control circuit goes dead — the thermostat goes blank, the system stops responding to calls for heating or cooling, and no error codes are generated because the board itself has no power.

• Specs: 40VA rating | 120V primary input | 24V secondary output | Matches OEM mounting footprint and terminal configuration for drop-in replacement
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by Carrier's control boards. Undersized or off-tolerance aftermarket units can overheat, trip thermal cutoffs, or cause erratic low-voltage behavior that mimics unrelated faults — wasting diagnostic time.
• Install difficulty: 2/5 — Shut off power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 24V output after install). Photograph all wiring connections before disconnecting. The transformer mounts inside the air handler cabinet and connects to the low-voltage wiring harness.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before cutoff ship same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier FX4DNF031T08ABAA fan coil air handler. Always verify your existing transformer's VA rating and voltage spec on the unit's data plate or original transformer label before ordering. Our fitment team is available to confirm compatibility before you purchase — no guesswork required. In stock and ready to ship today.