OEM Carrier Control Transformer 40VA 120V/24V for Model C4850C50ZX105610

This is the factory OEM replacement transformer (part# HT01BD236) for the Carrier C4850C50ZX105610 packaged unit. The control transformer steps down line voltage from 120V to 24V to power the low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this transformer fails, the entire control circuit goes dead: the thermostat loses power, nothing responds, and the system will not heat or cool. A failed transformer often presents as a completely unresponsive unit with no obvious mechanical damage.

• Specs: Input: 120VAC | Output: 24VAC | VA Rating: 40VA | OEM Part Number: HT01BD236 | Factory-matched for Carrier C4850C50ZX105610
• OEM vs Generic: This is the exact factory-specified transformer. OEM units are wound to precise VA tolerances ensuring consistent 24V output under full control-circuit load. Generic transformers often run under-rated VA, causing voltage sag that triggers nuisance lockouts and premature contactor coil failure.
• Install Difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify 0V across primary terminals before touching wiring. Photograph all connections before disconnecting. Reconnect leads to matching color-coded terminals and confirm 24V output before reassembling panel.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our HVAC parts warehouse.

Compatibility: Designed specifically for the Carrier C4850C50ZX105610 packaged unit. Verify your unit's control transformer input voltage (120V) and VA rating on the data plate or wiring diagram before ordering. If you're unsure of fitment, our parts specialists confirm compatibility before you purchase — no guesswork, no returns.