OEM Carrier Transformer 40VA 120V to 24V for Model C4850C50Z9105610

This is the factory OEM replacement transformer (part number HT01BD236) for the Carrier C4850C50Z9105610 packaged unit. The transformer steps down line voltage from 120V to the 24V signal required by your thermostat, control board, contactor coil, and all low-voltage control circuits. When this component fails, the entire control system loses power — the thermostat goes blank, the unit won't respond to any calls for heating or cooling, and no other diagnostics will progress until the transformer is replaced.

• Specs: 40VA rated | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory-matched output for full control circuit compatibility
• OEM vs Generic: OEM transformers are wound and insulated to exact factory VA and voltage specifications. Undersized or off-tolerance generic transformers can fail prematurely under peak load, damage connected control boards, or cause erratic system behavior.
• Install Difficulty: 2/5 — Disconnect power at the breaker before any work. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, wire nuts. Verify 24V output with a multimeter after installation before restoring full power. Always label wires before disconnecting.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C4850C50Z9105610 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltage on your unit's data plate before ordering. If your system still has no 24V control power after transformer replacement, inspect for a shorted low-voltage wire that may have caused the original failure. Our parts specialists are available to confirm fitment before you order — get the right part the first time and ship it today.