OEM Carrier Transformer 40VA 120V/24V for Model FA4ANF018008AGAA

This is the factory OEM replacement transformer (part number HT01CN236) for the Carrier FA4ANF018008AGAA air handler. The transformer steps down line voltage from 120V to the 24V AC required to power the entire low-voltage control circuit — including the thermostat, control board, contactor coil, and zone controls. When this transformer fails, the result is typically a completely unresponsive system: the thermostat goes blank, the air handler does nothing, and no fault codes appear because there is no control power to generate them. A failed transformer is often the first thing to check when a system is completely dead with no obvious cause.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01CN236 | Direct drop-in replacement with factory-matched mounting footprint and terminal configuration
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA rating and insulation class, ensuring stable 24V output under full control circuit load. Generic transformers are frequently undersized or poorly regulated, causing nuisance trips, control board brownouts, and premature contactor coil failure.
• Install difficulty: 2/5 — Shut off all power to the air handler before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter (to confirm 0V before touching terminals). Document or photograph existing wiring connections before disconnecting the old transformer. Typical replacement time is 15–25 minutes.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier FA4ANF018008AGAA air handler. Verify your existing transformer's primary voltage (120V), secondary voltage (24V), and VA rating (40VA) against your unit's data plate before ordering. If you are unsure of fitment, our HVAC parts specialists can confirm compatibility before your order ships — no guesswork required.