OEM Carrier 40VA Control Transformer for Model C4850C50Z3070600

This OEM control transformer (Carrier part# HT01BD236) is the factory-specified replacement for the Carrier C4850C50Z3070600 packaged unit. The transformer steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, gas valve, and all safety switches. When the transformer fails, the entire control circuit goes dead: the thermostat goes blank, nothing responds to a call for heat or cooling, and the system will not operate in any mode. A blown transformer is often caused by a short in the low-voltage wiring or a faulty component drawing excessive current.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched OEM dimensions and terminal configuration for drop-in replacement
• OEM vs Generic: OEM transformers (HT01BD236) are wound to exact Carrier factory specifications for VA capacity and thermal protection. Generic units are often underrated and more susceptible to burnout from minor wiring faults — a false economy on a critical component.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Before installing, use your multimeter to check the secondary circuit for shorts — replacing the transformer without clearing a short will burn the new unit immediately. Always label or photograph wiring before disconnecting.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered for Carrier model C4850C50Z3070600 packaged units. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. If you're unsure about fitment, our HVAC parts specialists can verify compatibility before you buy. Order today and your part ships the same business day.