OEM Carrier Control Transformer 40VA for Model C4850C50ZG055600

This OEM control transformer (part# HT01BD236) is the factory-specified replacement for the Carrier C4850C50ZG055600 packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers the control board, thermostat, contactor coil, and all low-voltage safety circuits. When this component fails, the entire control circuit goes dark — the thermostat goes blank, the system stops responding to calls for heating or cooling, and no error codes appear because the board itself has no power to generate them.

• Specs: 40VA output rating | Primary: 120V AC | Secondary: 24V AC | Class 2 transformer | Factory-wound coil with thermal overload protection | Replaces OEM part# HT01BD236
• OEM vs Generic: This OEM unit is wound to Carrier's exact VA rating and insulation class. Undersized or off-brand transformers can overheat under full 24V load, blow fuses repeatedly, or fail prematurely — especially in packaged units with multiple low-voltage accessories.
• Install difficulty: 2/5 — Disconnect all power at the breaker and verify with a voltmeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label all low-voltage leads before disconnecting the old transformer.
• Warranty: 1-year OEM factory warranty against defects. Orders placed by 3 PM local time ship same business day from our HVAC-dedicated warehouse.

Compatibility: Engineered specifically for the Carrier C4850C50ZG055600 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering. Our parts specialists are available to confirm fitment — reach out before you buy if you have any questions. In stock and ready to ship today.