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This OEM replacement transformer (part number HT01CN241) is the factory-specified control circuit transformer for the Carrier FY5BNF030T10AAAA fan coil unit. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, contactor coil, and any zone controls. When this transformer fails, nothing in the control system responds: the thermostat goes blank, the system won't call for heating or cooling, and you may find a blown fuse on the control board. It is one of the most commonly overlooked causes of a completely unresponsive HVAC system.
Compatibility: Designed for the Carrier FY5BNF030T10AAAA fan coil unit. Always confirm your unit's control circuit voltage and VA requirements on the data plate or wiring diagram before ordering. If your existing transformer shows signs of overheating or burning, inspect the control board fuse and any shorted wiring before installing the replacement. Our team is available to verify fitment — order with confidence.