OEM Carrier 40VA Control Transformer for Model C4850C50Z3060900

This OEM replacement control transformer (part# HT01BD236) is the factory-specified unit for the Carrier C4850C50Z3060900 packaged rooftop system. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When the transformer fails, the result is total system unresponsiveness: the thermostat goes blank, no heating or cooling calls are answered, and the unit sits completely dead despite line voltage being present at the unit.

• Specs: 40VA rated | 120V primary / 24V secondary | Class 2 transformer | Factory-matched output for full control circuit load
• OEM vs Generic: OEM transformers like this HT01BD236 are wound to Carrier's exact VA tolerance and insulation class. Undersized or off-brand units can sag under load, causing intermittent lockouts or premature failure of downstream control boards.
• Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 24V output post-install). Photograph or label all low-voltage wiring before disconnecting from the old transformer's secondary terminals.
• Warranty: 1-year OEM factory warranty against defects. Orders ship same business day from our stocked warehouse.

Compatibility: Engineered as a direct OEM drop-in for the Carrier C4850C50Z3060900 packaged unit. Always verify your unit's control circuit voltage and VA requirements on the data plate before ordering. Our fitment team is available to confirm compatibility before you buy — no guesswork required.