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This OEM control transformer (part number HT01CN241) is the factory-specified replacement for the Carrier FB4CNP018L08ACAA fan coil air handler. The transformer steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When this component fails, the entire control system goes dark: your thermostat loses power, the system stops responding to calls for heating or cooling, and nothing works. A failed transformer is often misdiagnosed as a bad thermostat or control board, making it a critical first diagnostic check.
Compatibility: Engineered for the Carrier FB4CNP018L08ACAA fan coil air handler. Verify the transformer's VA rating and voltage on your unit's data plate before ordering to confirm fitment. Our team is available to verify compatibility before you purchase — same-day shipping available on all in-stock orders.