OEM Carrier Control Transformer 40VA for Model C4850C50AJ06051

This is the genuine OEM replacement transformer (part# HT01BD236) for the Carrier C4850C50AJ06051 packaged unit. The control transformer steps down 120V line voltage to the 24V signal required by your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this part fails, the entire control circuit goes dark — the thermostat goes blank, the system won't respond to any calls for heating or cooling, and no fault codes will display because there's no power to generate them. A failed transformer is often misdiagnosed as a bad thermostat or control board, making this an important first diagnostic check.

• Specs: 40VA rating | Primary: 120VAC | Secondary: 24VAC | OEM part number HT01BD236 | Factory-matched output for Carrier low-voltage control circuits
• OEM vs Generic: This OEM transformer is wound to exact Carrier specifications, ensuring stable 24V output under full load. Generic transformers frequently run undervoltage at full draw, causing erratic contactor chatter, nuisance lockouts, and premature control board failure.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label all wiring before removal. Verify 24VAC output with a multimeter after installation before restoring full system power.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before 3PM EST ship same business day from our stocked warehouse.

Compatibility: Designed specifically for the Carrier C4850C50AJ06051 packaged unit. Always verify your existing transformer's VA rating and primary/secondary voltages from the data plate before ordering. If you're unsure of fitment, our HVAC parts team is available to confirm compatibility before you purchase — just reach out with your unit's full model and serial number.