OEM Carrier Control Transformer 40VA 120V/24V for Model C4850C50Z3070200

This OEM replacement transformer (part number HT01BD236) is the factory-specified step-down transformer for the Carrier C4850C50Z3070200 packaged unit. The transformer converts 120V line voltage down to the 24V signal used by the control board, thermostat, contactor coil, and all low-voltage safety circuits. When this component fails, the entire control circuit goes dead — the thermostat shows no response, the contactor never energizes, and the system will not heat or cool under any circumstance. It is often the first component to diagnose when a unit appears completely unresponsive.

• Specs: 40VA rated | Primary: 120VAC | Secondary: 24VAC | OEM part number HT01BD236 | Factory-matched output for stable low-voltage control operation
• OEM vs Generic: This OEM transformer meets Carrier's exact VA rating and winding tolerances. Undersized or off-spec generic transformers can overheat, trip the integral fuse, or deliver unstable 24V output that causes nuisance control board faults and contactor chatter.
• Install difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Photograph all wiring connections before removal. The transformer mounts to the control panel with a single bracket screw on most configurations.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock units ship same business day from our climate-controlled warehouse.

Compatibility: Designed for the Carrier C4850C50Z3070200 packaged unit. Always verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring schematic before ordering — some unit variants may use a 40VA transformer with a built-in fuse holder. Our HVAC parts specialists are available to confirm fitment before you purchase. Order today and receive same-day shipping on all in-stock parts.