OEM Carrier Control Transformer 40VA for Model C4850C50ZG075610

This OEM replacement control transformer (part# HT01BD236) is the factory-specified unit for the Carrier C4850C50ZG075610 packaged heating and cooling system. The transformer steps down line voltage (120V) to the 24V signal voltage that powers your thermostat, control board, contactor coil, and all low-voltage safety circuits. When it fails, absolutely nothing responds — the thermostat goes dark, the system won't call for heating or cooling, and no fault codes appear because the control board itself has lost power. A failed transformer is often mistaken for a bad thermostat or control board, making correct diagnosis critical before ordering parts.

• Specs: 40VA capacity | 120V primary input | 24V secondary output | Class 2 rating | Replaces OEM part number HT01BD236 | Factory-matched construction and terminal configuration
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances for this unit. Undersized or off-tolerance generic units can overheat, trip their internal thermal fuse, or cause erratic low-voltage behavior — putting your control board at risk.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (verify 0V before touching terminals). Label all low-voltage wires before disconnecting. Confirm primary voltage with meter after reinstallation before restoring power.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C4850C50ZG075610 packaged unit. Verify your existing transformer's primary voltage, secondary voltage, and VA rating on the unit's data plate or wiring diagram before ordering. Unsure of fitment? Contact our HVAC parts specialists — we confirm compatibility before you buy.