OEM Carrier Transformer 40VA 120V/24V for Model FY5BNF018T08AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified step-down transformer for the Carrier FY5BNF018T08AAAA fan coil unit. The transformer converts 120V line voltage to the 24V AC signal required to power the control board, thermostat, and all low-voltage control circuit components. When this transformer fails, the entire control circuit goes dead — the thermostat loses power, relays won't energize, and the system will not respond to any heating or cooling calls. If your system appears completely unresponsive and a multimeter shows no 24V output at the secondary terminals, this transformer is the most likely culprit.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Class 2 transformer | Mounts to standard bracket inside air handler cabinet
• OEM vs Generic: The OEM HT01CN241 transformer is wound and encapsulated to Carrier's exact VA and voltage tolerance specifications. Generic substitutes may deliver inconsistent secondary voltage, causing control board resets, erratic thermostat behavior, or premature board failure — making OEM the only reliable choice.
• Install difficulty: 2/5 — Shut off power at the breaker and verify with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph all wiring connections before disconnecting. Swap primary and secondary leads to matching terminals and restore power to verify 24V output.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse.

Compatibility: Designed and factory-matched for the Carrier FY5BNF018T08AAAA fan coil unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit's data plate or wiring diagram before ordering. Our HVAC parts specialists are available to confirm fitment prior to purchase. Order before 3PM EST for same-day shipping.