OEM Carrier Control Transformer 40VA 120V/24V for Model FB4CNF036T10ACAA

This is the factory OEM replacement control transformer (part number HT01CN241) for the Carrier FB4CNF036T10ACAA fan coil air handler. The transformer steps down line voltage from 120V to 24V to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, the entire control circuit goes dark: the thermostat loses power, relays won't energize, and the system refuses to respond to any call for heating or cooling. A failed transformer is often mistaken for a bad thermostat or control board, making correct diagnosis critical before replacing more expensive components.

• Specs: 40VA rated | Primary: 120V | Secondary: 24V | OEM part number HT01CN241 | Factory-matched for Carrier FB4CNF036T10ACAA air handlers
• OEM vs Generic: This OEM transformer meets Carrier's exact VA rating and insulation class requirements. Undersized generic transformers commonly overheat under full control-circuit load, causing nuisance tripping or premature failure and risking damage to the connected control board.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label all wiring connections before disconnecting. Verify 24V output at secondary terminals after installation before restoring full system power.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed and factory-specified for the Carrier FB4CNF036T10ACAA fan coil air handler. Verify your unit's control circuit voltage and VA requirements on the data plate before ordering. Not sure if this is the right part? Our HVAC parts specialists confirm fitment before every order — reach out before you buy.