OEM Carrier 40VA Control Transformer HT01CN241 for Model FX4BNF018000AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified control circuit transformer for the Carrier FX4BNF018000AAAA fan coil air handler. Its sole but critical job is to step down line voltage (120V) to the 24V AC signal that powers your thermostat, control board, contactor coil, and every other low-voltage component in the system. When this transformer fails, absolutely nothing in the control circuit responds — the thermostat goes dark, the system won't call for heating or cooling, and the unit sits completely unresponsive despite having full line power. It is one of the first components to test when diagnosing a completely dead HVAC system.

• Specs: 40VA rated | 120V primary / 24V secondary | OEM part number HT01CN241 | Factory-matched output for Carrier low-voltage control circuits
• OEM vs Generic: This OEM transformer is wound and tested to Carrier's exact VA and voltage output specifications. Generic transformers can produce slightly off-voltage output (±10%), which stresses sensitive control boards and thermostats, potentially causing nuisance lockouts or premature board failure.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label or photograph all low-voltage wiring before disconnecting. Verify output voltage with a multimeter before closing the panel.
• Warranty: 1-year OEM factory warranty. In-stock and ships the same business day from our climate-controlled warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier FX4BNF018000AAAA fan coil air handler. Always confirm the VA rating and primary/secondary voltages on your unit's data plate match before ordering. Our parts specialists are available to verify fitment — order with confidence and get your system back online today.