OEM Carrier Control Transformer 40VA for Model C4850C50ZN060500

This is the factory OEM replacement control transformer (part# HT01BD236) for the Carrier C4850C50ZN060500 packaged gas/electric unit. The transformer steps down 120V line voltage to the 24V signal used by your thermostat, control board, contactor coil, and gas valve. When this component fails, the entire control circuit goes dark — the thermostat loses power, nothing responds, and the system will not attempt a heat or cool cycle. If you've confirmed 120V supply voltage at the unit but have no 24V at the secondary terminals, this transformer is almost certainly the cause.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory-wound core for precise voltage regulation under full control-circuit load
• OEM vs Generic: The OEM HT01BD236 transformer is wound to Carrier's exact VA and impedance specifications, ensuring stable 24V output even when all control loads (contactor coil, gas valve, board) are energized simultaneously. Undersized or off-tolerance generic transformers can sag voltage under load, causing random lockouts and nuisance trips.
• Install difficulty: 2/5 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label or photograph all 24V wire connections before removing the old unit. Verify 0V on primary terminals with your meter before touching any leads.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C4850C50ZN060500 packaged unit. Always confirm your existing transformer's primary voltage, secondary voltage, and VA rating on the unit data plate or wiring diagram before ordering. Our fitment team is available to verify compatibility prior to purchase — same-day shipping on all in-stock orders.