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This is the OEM factory-specified control transformer (part number HT01BD209) for the Carrier FIOP100301GA. The transformer steps down line voltage from 120V to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, and control board logic. When this component fails, the entire control circuit loses power: the thermostat goes blank, no calls for heating or cooling are processed, and the system is completely unresponsive. It is often the first component to inspect when nothing works but the breaker is confirmed on.
Compatibility: Designed for the Carrier FIOP100301GA unit. Always verify the primary voltage, secondary voltage, and VA rating on your existing transformer's label before ordering to ensure a correct fit. Our parts specialists are available to confirm compatibility before you purchase — order with confidence and get back up and running fast.