OEM Carrier Transformer 40VA 120V/24V for Model C4850C48ZN040600

This is the OEM factory-specified control circuit transformer (part number HT01BD236) for the Carrier C4850C48ZN040600 packaged unit. The transformer steps down 120V line voltage to 24V to power the entire control circuit — including the thermostat, contactor coil, and control board. When this component fails, the entire system goes silent: no thermostat response, no staging, no operation of any kind. A blown transformer is often the last thing techs check but one of the most common causes of a completely unresponsive HVAC system.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory-matched for Carrier packaged unit applications
• OEM vs Generic: This is a genuine OEM Carrier transformer wound to exact VA and voltage specifications. Generic transformers often use thinner copper windings rated at lower thermal thresholds, leading to premature failure — especially in packaged units exposed to ambient heat.
• Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Always confirm secondary voltage output (should read 24–28V AC) before buttoning up the unit. Label wires before disconnecting old transformer.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier C4850C48ZN040600 packaged unit. Verify your unit's control voltage requirements on the data plate and confirm the 40VA rating matches your system's control load before ordering. Our HVAC parts specialists are available to verify fitment — reach out before you order if you have any questions.