OEM Carrier Transformer 40VA 120V to 24V for Model FX4BNF030000AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified control circuit transformer for the Carrier FX4BNF030000AAAA fan coil air handler. The transformer steps line voltage (120V) down to the 24V low-voltage signal that powers your thermostat, control board, and all relay coils throughout the system. When this component fails, the entire control circuit goes dark — you'll see a blank thermostat, an unresponsive system, or a tripped secondary fuse with no obvious cause. It is one of the first components to test when nothing works at all.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01CN241 | Factory-matched output for stable low-voltage control circuit operation
• OEM vs Generic: This is the genuine OEM Carrier transformer, wound to exact VA and voltage tolerances. Undersized or off-tolerance generic transformers can overheat, trip the secondary fuse repeatedly, or deliver unstable 24V that causes erratic board behavior and misdiagnosis.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdriver, multimeter, wire nuts or spade connectors. Always verify 0V at primary terminals before touching wiring. Label all low-voltage leads before removal.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier FX4BNF030000AAAA fan coil air handler. Confirm your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering. If you're unsure of fitment, our parts specialists are available to verify compatibility before you purchase — same-day shipping guaranteed on all in-stock orders.