OEM Carrier Control Transformer 40VA for Model FB4CNF018008ABAA

This OEM control transformer (part# HT01CN241) is the factory-specified replacement for the Carrier FB4CNF018008ABAA fan coil unit. The transformer steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, and any connected control boards. When this transformer fails, the entire control circuit goes dead: the thermostat goes blank, the system refuses to respond to any call for heating or cooling, and you may find a blown fuse on the control board caused by a shorted secondary winding.

• Specs: 40VA rated | Primary: 120V AC | Secondary: 24V AC | Factory-matched OEM replacement | Part Number: HT01CN241
• OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the FB4CNF018008ABAA control circuit. Generic transformers often use lower-grade core laminations, leading to overheating under full load and premature failure — especially when accessory loads like humidifiers or UV lights share the 24V circuit.
• Install difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Always verify 0V at the primary terminals before disconnecting wiring. Photograph all wiring connections prior to removal.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier FB4CNF018008ABAA fan coil unit. Verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering. If you're unsure of fitment, our HVAC parts specialists are available to confirm compatibility before you buy — no guesswork required.