OEM Carrier Transformer 40VA 120V/24V for Model FX4ANF018000ACAA

This OEM step-down transformer (part# HT01CN236) is the factory-specified replacement for the Carrier FX4ANF018000ACAA fan coil air handler. The transformer converts 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When the transformer fails, the result is total control loss: the thermostat goes dark, the system won't respond to any call for heating or cooling, and no 24V is present at the control board terminals.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched Carrier OEM part number HT01CN236 | Designed for continuous duty in air handler applications
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact VA and voltage tolerances. Generic transformers often run under-rated VA, causing premature overload failure — especially in systems with multiple 24V accessories such as humidifiers, UV lights, or zone boards.
• Install difficulty: 2/5 — Shut off all power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (to verify 24V output after installation). Label and photograph all wiring connections before disconnecting the old unit.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier FX4ANF018000ACAA fan coil air handler. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering. If you are unsure of fitment, our HVAC parts specialists are available to confirm compatibility before you purchase. Order today for same-day shipping.