OEM Carrier Transformer 40VA 120V/24V for Model FF1DNA018000AAAA

This is the factory OEM replacement transformer (part number HT01CN236) for the Carrier FF1DNA018000AAAA air handler. The transformer steps down 120V line voltage to the 24V control circuit voltage required to power your thermostat, contactor coil, and control board. When the transformer fails, the entire control circuit loses power — symptoms include a completely unresponsive thermostat, no system operation at all, or a blown low-voltage fuse caused by a shorted secondary winding.

• Specs: 40VA rating | 120V primary input | 24V secondary output | Factory-matched OEM winding tolerances | UL-listed construction | Part Number: HT01CN236
• OEM vs Generic: This OEM Carrier transformer is wound to exact factory VA and voltage specifications. Generic transformers often run undersized VA ratings, causing premature burnout when multiple 24V accessories (humidifiers, zone boards, communicating stats) draw combined load.
• Install difficulty: 2/5 — Shut off all power to the air handler at the disconnect and breaker before beginning. Tools needed: flat-head and Phillips screwdrivers, wire stripper, multimeter (to confirm 0V before touching wiring). Note wire colors and terminal positions before disconnecting the old unit.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier FF1DNA018000AAAA fan coil air handler. Verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering. Our fitment team is available to confirm compatibility prior to purchase — order with confidence and receive same-day shipping on in-stock OEM parts.