OEM Carrier Control Transformer 40VA 120V–24V for Model FX4CNF048T00AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified step-down transformer for the Carrier FX4CNF048T00AAAA fan coil air handler. The transformer converts 120V line voltage to the 24V AC signal that powers the control board, thermostat circuit, and all low-voltage components in the system. When the transformer fails, the result is total system unresponsiveness — the thermostat goes blank, the air handler won't respond to calls for cooling or heating, and no low-voltage components receive power. A failed transformer is often mistaken for a bad control board, making correct diagnosis critical before ordering parts.

• Specs: 40VA output rating | 120V primary / 24V secondary | Class 2 rated | Factory-matched OEM tolerance for the Carrier FX4CNF048T00AAAA air handler
• OEM vs Generic: This is a genuine OEM Carrier transformer (HT01CN241) built to exact factory VA and voltage specifications. Generic transformers frequently fall short of rated VA capacity, causing nuisance tripping, overheating, and premature control board failure due to voltage sag under load.
• Install Difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Confirm secondary output reads 24–28V AC before restoring full system power. Note wire colors and terminal labeling before disconnecting the old unit.
• Warranty: 1-year OEM factory warranty against defects. In-stock units ship same business day from our warehouse when ordered before cutoff.

Compatibility: Designed specifically for the Carrier FX4CNF048T00AAAA 4-ton fan coil air handler. Always verify your existing transformer's primary voltage, secondary voltage, and VA rating against your unit's data plate before ordering to ensure a correct fit. Our parts specialists are available to confirm compatibility prior to purchase.