OEM Carrier 40VA Control Transformer for Model FX4DNF031L08ABAA

This OEM replacement transformer (part# HT01CN241) is the factory-specified control circuit transformer for the Carrier FX4DNF031L08ABAA air handler. It steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, control board, and zone controls. When this transformer fails, the entire control circuit goes dark: your thermostat loses power, the air handler won't respond to any commands, and the system appears completely dead despite having line voltage at the unit.

• Specs: 40VA rated | 120V primary / 24V secondary | Factory OEM part number HT01CN241 | Hardwired lead terminations | Meets UL listing requirements for residential HVAC applications
• OEM vs Generic: This OEM transformer is wound to exact Carrier factory tolerances, ensuring stable 24V output under full load. Generic transformers frequently under-deliver VA capacity, causing nuisance tripping of the internal thermal fuse and premature failure — especially when multiple zones or accessories are connected to the 24V circuit.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, needle-nose pliers, multimeter (to confirm 24V output after installation). Label or photograph all low-voltage wiring before disconnecting. Typical service call replacement time is 20–30 minutes.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed and factory-matched for the Carrier FX4DNF031L08ABAA fan coil air handler. Always verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering to confirm fitment. Have a question about compatibility? Our HVAC parts specialists verify fitment before you order — call or chat today. In stock — ships today.