OEM Carrier Transformer 40VA 120V to 24V for Model FB4BNL024L00AAAA

This is the factory OEM replacement transformer (part number HT01CN241) for the Carrier FB4BNL024L00AAAA fan coil air handler. The transformer steps down 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When the transformer fails, absolutely nothing in the system responds: the thermostat goes blank, the unit won't call for cooling or heating, and no relays or contactors will energize. A failed transformer is often caused by a short in the 24V control wiring or an oversized fuse, so inspect the secondary circuit before installing the replacement.

• Specs: 40VA rating | Primary voltage: 120V AC | Secondary voltage: 24V AC | OEM part number HT01CN241 | Factory-matched to Carrier FB4BNL024L00AAAA control circuit requirements
• OEM vs Generic: This OEM unit is wound and rated to exact factory VA specifications, ensuring the 24V control circuit receives stable, consistent voltage. Undersized or off-spec generic transformers can cause nuisance lockouts, relay chatter, and premature control board failure.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Always verify 24V output on the secondary side with a multimeter before reconnecting the thermostat wiring.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our climate-controlled warehouse.

Compatibility: Engineered specifically for the Carrier FB4BNL024L00AAAA fan coil air handler. Confirm your unit's data plate shows 120V primary input before ordering. If you are unsure of fitment, our HVAC parts specialists are available to verify compatibility before you purchase — same-day shipping guaranteed on all in-stock orders placed before 3 PM local time.