OEM Carrier Control Transformer 40VA for Model FA4ANF018008AFAA

This OEM control transformer (part# HT01CN236) is the factory-specified replacement for the Carrier FA4ANF018008AFAA air handler. The transformer steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, control board, and zone valves. When this component fails, the entire control system goes dark: the thermostat becomes unresponsive, the system won't call for heating or cooling, and no error codes will display because the board itself has lost power.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01CN236 | Factory-matched for Carrier FA4ANF018008AFAA air handlers
• OEM vs Generic: This is a genuine OEM Carrier transformer, wound to exact VA and voltage tolerances. Undersized or off-tolerance generic transformers can overheat under full control load, blow internal fuses, or deliver insufficient voltage to the control board — causing erratic operation or repeat failures.
• Install Difficulty: 2/5 — Disconnect power at the breaker and confirm voltage is absent with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or quick-connects. Label all low-voltage wires before removal. Check for a shorted thermostat wire or stuck contactor coil before installing the new transformer — these are the most common causes of transformer failure.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier FA4ANF018008AFAA air handler. Verify your unit's control circuit voltage requirements on the data plate before ordering — most residential air handlers use 24V/40VA, but commercial or multi-zone applications may require a higher VA rating. Our fitment team is available to confirm compatibility before you order. Order today and receive same-day shipping on all in-stock parts.