OEM Carrier 40VA Control Transformer HT01BD236 for Model C4850C48Z8075610

This OEM control transformer is the factory-specified replacement for the Carrier C4850C48Z8075610 packaged unit. The transformer steps down 120V line voltage to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this component fails, the entire system goes silent: the thermostat goes blank, no calls for heating or cooling are processed, and nothing responds. A failed transformer is one of the most common root causes of a completely unresponsive HVAC system.

• Specs: 40VA rated | 120V primary / 24V secondary | OEM part number HT01BD236 | Factory-matched insulation class and terminal configuration for direct drop-in replacement
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA rating and insulation specifications. Undersized or off-brand transformers can overload under peak demand — especially when multiple accessories draw current simultaneously — leading to premature failure and potential control board damage.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Always label or photograph existing wiring before disconnecting terminals.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for use in the Carrier C4850C48Z8075610 packaged unit. Always verify your existing transformer's VA rating and primary/secondary voltage on the unit's data plate or wiring schematic before ordering. Our fitment team is available to confirm compatibility before you buy — just reach out with your model and serial number.