OEM Carrier 40VA Control Transformer for Model FX4DNF061T00ABAA — Part# HT01CN241

This OEM replacement transformer (part# HT01CN241) is the factory-specified control circuit transformer for the Carrier FX4DNF061T00ABAA fan coil air handler. The transformer steps down 120V line voltage to 24V AC, powering the thermostat, control board, contactor coil, and all low-voltage control wiring throughout your system. When this component fails, the entire control circuit goes dark — the thermostat loses power, the system refuses to respond to any calls for heating or cooling, and in many cases the control board itself appears dead. A failed transformer is one of the most commonly misdiagnosed faults in air handler service calls.

• Specs: 40VA rated | Primary: 120V AC | Secondary: 24V AC | Factory-matched OEM design | Compatible with standard 24V thermostat and control board circuits
• OEM vs Generic: This OEM unit is wound and rated to Carrier's exact factory tolerances, ensuring stable 24V output under full VA load. Generic transformers frequently under-deliver on VA capacity, causing nuisance lockouts or premature control board damage under peak demand.
• Install difficulty: 2/5 — Shut off all power to the air handler at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label or photograph all low-voltage wiring connections before disconnecting. Typical install time: 20–30 minutes for an experienced DIYer.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before cutoff ship the same business day from our climate-controlled parts warehouse.

Compatibility: Engineered specifically for the Carrier FX4DNF061T00ABAA fan coil air handler. Always verify your existing transformer's VA rating and primary/secondary voltages on the data plate or wiring diagram before ordering. Our parts specialists are available to confirm fitment — reach out before you buy if you have any questions. In stock and ships today.