OEM Carrier Transformer 40VA 120V to 24V for Model FV4BNB006T00AAAA

This OEM replacement transformer (part number HT01CN236) is the factory-specified control circuit transformer for the Carrier FV4BNB006T00AAAA fan coil air handler. The transformer steps down 120V line voltage to the 24V AC signal required to power the thermostat, control board, and all low-voltage components. When the transformer fails, the entire control circuit goes dead — your thermostat will go blank, the system will not respond to any calls for heating or cooling, and no relays or contactors will energize. This is one of the most commonly overlooked causes of a completely non-responsive HVAC system.

• Specs: 40VA rated | Primary: 120V AC | Secondary: 24V AC | Factory OEM part number HT01CN236 | Designed for Carrier fan coil applications
• OEM vs Generic: OEM transformers are wound and insulated to exact Carrier factory tolerances, ensuring stable 24V output under full control-circuit load. Generic substitutes may sag under load, causing erratic thermostat behavior, nuisance lockouts, and premature control board failure.
• Install difficulty: 2/5 — Disconnect power to the air handler at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify 0V at primary terminals before touching wiring. Note secondary wire connections before disconnecting the old transformer.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier FV4BNB006T00AAAA fan coil air handler. Confirm your existing transformer's VA rating and primary/secondary voltages on the unit's data plate or wiring diagram before ordering. Our parts specialists are available to verify fitment prior to purchase — reach out before you order if you have any questions.