OEM Carrier Transformer 40VA 120V to 24V for Model C4850C50ZX075610

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C4850C50ZX075610 packaged unit. The transformer steps line voltage (120V) down to the 24V signal used by your thermostat, control board, contactor coil, and all low-voltage components. When this part fails, the entire control circuit goes dark — the thermostat goes blank, the system refuses to respond to any call for heating or cooling, and no safety controls can operate. A blown transformer is often the first suspect when absolutely nothing works after a power surge or a shorted low-voltage wire.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory wire leads for direct reconnection
• OEM vs Generic: This factory OEM transformer is wound to exact VA and voltage tolerances for the C4850C50ZX075610. Generic transformers with undersized VA ratings can overheat and fail prematurely, especially when multiple 24V accessories (humidifiers, zoning boards, UV lights) are connected to the circuit.
• Install difficulty: 2/5 — Disconnect power at the disconnect box and confirm zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Always identify and correct any low-voltage short before installing the new transformer — a shorted thermostat wire will blow the new unit immediately.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C4850C50ZX075610 packaged unit. Verify primary voltage and VA rating on your existing transformer's label before ordering. If your unit has additional 24V accessories installed, confirm total VA load does not exceed 40VA. Our parts specialists are available to verify fitment before you order — no guesswork required.