OEM Carrier 40VA Control Transformer HT01CN241 for Model FX4DNF043L00ABAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified 40VA step-down transformer for the Carrier FX4DNF043L00ABAA fan coil air handler. The transformer converts 120V line voltage to the 24V AC signal that powers your system's entire control circuit — including the thermostat, contactor coil, and control board. When it fails, the result is typically a completely unresponsive system: the thermostat goes blank, the blower won't start, and no call for heating or cooling is processed. A failed transformer can also blow the 3A control fuse repeatedly, which is a telltale sign before total failure.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01CN241 | Factory-matched output for stable control circuit operation
• OEM vs Generic: This is the genuine Carrier OEM transformer, wound and insulated to exact factory specifications. Generic replacements may have looser VA tolerances and lower-quality insulation, risking under-voltage conditions that cause nuisance lockouts or premature control board failure.
• Install difficulty: 2/5 — Always disconnect power at the breaker before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 24V output after install). Label or photograph all wiring connections before disconnecting the old transformer.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier FX4DNF043L00ABAA fan coil air handler. Confirm your unit's data plate shows 120V primary control voltage before ordering. If you're unsure of fitment, our HVAC parts specialists are available to verify compatibility before you purchase — same-day shipping available on all in-stock orders.