OEM Carrier Transformer 40VA 120V/24V for Model FC4DNF030005AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified step-down transformer for the Carrier FC4DNF030005AAAA fan coil unit. The transformer converts 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage system controls. When this component fails, the entire control circuit goes dead — your thermostat goes blank, the system won't respond to any commands, and the unit sits completely unresponsive despite power being present at the unit.

• Specs: 40VA output rating | 120V primary input | 24V secondary output | Direct OEM replacement for part number HT01CN241 | Factory-matched impedance and VA rating
• OEM vs Generic: OEM transformers are wound to exact Carrier factory specifications, ensuring correct VA output under load. Undersized or off-spec generic transformers can overheat, blow internal fuses, or fail to sustain 24V under full control-circuit demand — leading to nuisance lockouts and callbacks.
• Install Difficulty: 2/5 — Shut off all power to the unit at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Label or photograph all low-voltage wiring before disconnecting terminals.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our warehouse stock.

Compatibility: Designed as a direct OEM replacement for the Carrier FC4DNF030005AAAA fan coil unit. Verify your existing transformer's primary voltage (120V), secondary voltage (24V), and VA rating on the component label or unit data plate before ordering. Our fitment team is available to confirm compatibility prior to purchase — same-day shipping on all in-stock orders.