OEM Carrier 40VA Control Transformer HT01CN241 for Model FY5BNF030000AAAA

This OEM Carrier transformer (part number HT01CN241) is the factory-specified replacement for the FY5BNF030000AAAA fan coil unit. The transformer's job is to step down line voltage (120V) to the 24V AC required by your thermostat, control board, contactor coil, and all low-voltage control circuits. When the transformer fails, the entire control system goes dark — the thermostat loses power, the system won't respond to any calls for heating or cooling, and nothing works. It is often the first component to inspect when a unit shows zero response despite having power at the disconnect.

• Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01CN241 | Factory-matched output voltage and VA capacity for the FY5BNF030000AAAA control circuit
• OEM vs Generic: OEM transformers are wound to exact VA tolerances, protecting downstream components like the control board and contactor coil from voltage sag under load. Generic units with underrated VA can cause erratic behavior, nuisance lockouts, and premature board failure.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter to confirm 0V before touching terminals. Label or photograph all low-voltage wire connections before disconnecting the old unit.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier FY5BNF030000AAAA fan coil unit. Confirm your existing transformer's primary voltage (120V), secondary voltage (24V), and VA rating on the unit data plate or existing transformer label before ordering. Our fitment team is available to verify compatibility prior to purchase — same-day shipping available on all in-stock orders.