OEM Carrier Control Transformer 40VA 120V/24V for Model C48A402552

This is the factory OEM replacement control transformer (part number HT01BD236) for the Carrier C48A402552 packaged unit. The transformer steps down line voltage from 120V to the 24V signal required by your thermostat, contactor coil, and control board. When it fails, the entire control circuit goes dead — your thermostat goes blank, the system won't respond to any call for heating or cooling, and nothing turns on. If you have 120V at the primary but zero volts at the secondary, this transformer is the culprit.

• Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD236 | Factory-matched construction for Carrier packaged equipment
• OEM vs Generic: This is the genuine OEM unit built to Carrier's exact VA rating and insulation class. Generic transformers often carry undersized VA ratings that overheat under full control-circuit load, leading to premature failure and nuisance tripped breakers.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Confirm 0V at the primary terminals before handling. Label all wire connections before removal and match wire-for-wire on reinstall.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Engineered as a direct OEM fit for the Carrier C48A402552 packaged unit. Verify your existing transformer's primary voltage, secondary voltage, and VA rating on the unit's data plate before ordering to ensure a match. Have questions about fitment? Our HVAC parts specialists will verify compatibility before your order ships.