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This OEM replacement transformer (part number HT01CN236) is the factory-specified control circuit transformer for the Carrier FV4CNF005T00ABAA fan coil unit. The transformer steps down 120V line voltage to the 24V signal voltage required to power your thermostat, control board, and all low-voltage control wiring. When this component fails, the entire control circuit goes dead — the thermostat loses power, relays won't energize, and the system becomes completely unresponsive. A failed transformer is often diagnosed by confirming 120V input at the primary but 0V output at the secondary terminals.
Compatibility: This transformer is engineered specifically for the Carrier FV4CNF005T00ABAA fan coil unit. Always verify your existing transformer's input voltage, output voltage, and VA rating against your unit's data plate before ordering. Our parts specialists are available to confirm fitment — order with confidence and get your system back online fast.