OEM Carrier Control Transformer 40VA 120V/24V for Model C48A502552

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C48A502552 packaged unit. The transformer steps down line voltage from 120V to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When this component fails, the system goes completely unresponsive: the thermostat goes blank, the unit will not energize, and no heating or cooling calls are answered. A failed transformer is one of the most commonly misdiagnosed "dead system" faults in packaged HVAC equipment.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BD236 | Factory-matched to Carrier C48A502552 control circuit requirements
• OEM vs Generic: This OEM transformer meets Carrier's exact VA rating and insulation class specifications. Undersized or off-brand transformers can overheat, trip their internal fuse repeatedly, or fail to sustain 24V under full control circuit load — leading to nuisance lockouts and callbacks.
• Install Difficulty: 2/5 — Disconnect power at the disconnect box and verify zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Always label or photograph existing wiring before removal.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C48A502552 packaged unit. Confirm your existing transformer's primary voltage, secondary voltage, and VA rating on the data plate before ordering to ensure a proper fit. Our HVAC parts specialists are available to verify fitment before you purchase — order with confidence and get your system back online fast.