OEM Carrier Control Transformer 40VA 120V/24V for Model C4850C50Z3070500

This OEM replacement control transformer (part number HT01BD236) is the factory-specified unit for the Carrier C4850C50Z3070500 packaged HVAC system. The transformer steps down line voltage from 120V to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, the entire control circuit goes dark: the thermostat goes blank, the system won't respond to any call for heating or cooling, and no safety or staging functions operate. It is often the first component to diagnose when nothing works at all.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BD236 | Factory-matched output for Carrier low-voltage circuits
• OEM vs Generic: This is the genuine OEM Carrier transformer, wound and rated to exact factory specifications. Generic transformers frequently run undervoltage under load, causing erratic control board behavior, nuisance lockouts, and premature contactor coil failure.
• 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 installation). Label or photograph all low-voltage wire connections before disconnecting. Primary wires carry 120V — confirm power is off before touching.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships the same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C4850C50Z3070500 packaged unit. Always verify your unit's data plate and existing transformer VA and voltage ratings before ordering. Our HVAC parts specialists are available to confirm fitment prior to purchase — don't guess on control circuit components.