OEM Carrier Control Transformer 40VA 120V/24V for Model C50A203551

This is the factory OEM replacement transformer (part# HT01BD236) designed for the Carrier C50A203551 commercial rooftop unit. The transformer steps down 120V line voltage to the 24V control circuit voltage required by your thermostat, contactor coil, gas valve, and all low-voltage controls. When this transformer fails, the entire control circuit goes dark — symptoms include a completely unresponsive thermostat, a contactor that won't energize, or a system that won't respond to any call for heat or cooling despite line voltage being present at the unit.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | Factory-matched OEM part number HT01BD236 | Designed for Carrier C50A203551 commercial rooftop platform
• OEM vs Generic: This OEM transformer is wound to exact Carrier specifications, ensuring proper VA capacity and voltage regulation under full control-circuit load. Undersized or generic transformers can cause erratic low-voltage behavior, nuisance tripping, or premature failure of downstream components like contactors and gas valves.
• Install Difficulty: 3/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, and insulated terminals. Confirm primary and secondary wiring labels before disconnecting old unit. A blown transformer may indicate a low-voltage short — check wiring for faults before installing replacement.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our HVAC parts warehouse.

Compatibility: Engineered specifically for the Carrier C50A203551 commercial rooftop unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering to confirm fitment. Our parts specialists are available to verify compatibility before you purchase — don't guess on a control circuit component.