OEM Carrier Control Transformer 40VA 120V/24V for Model C4850C48ZT105610

This is the factory OEM replacement transformer (part# HT01BD236) for the Carrier C4850C48ZT105610 packaged unit. The transformer steps down 120V line voltage to 24V AC to power the entire control circuit — including the thermostat, contactor coil, gas valve solenoid, and control board. When this component fails, absolutely nothing in the low-voltage control circuit responds: the thermostat goes blank or unresponsive, the system won't call for heating or cooling, and no safety controls can operate. A blown transformer is often the first clue when a system is completely "dead" despite line voltage being present.

• Specs: 40VA rating | 120V primary / 24V secondary | Class 2 transformer | Hardwired lead connection | OEM part number HT01BD236
• OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the C4850C48ZT105610 control board load. Undersized or off-tolerance generic units can overheat, trip their internal breaker repeatedly, or fail to sustain 24V under full control-circuit load — leading to intermittent lockouts and nuisance service calls.
• Install difficulty: 2/5 — Shut off power at the disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, wire strippers, multimeter (confirm 0V before touching leads). Photograph existing wiring before disconnecting. Match primary and secondary lead colors exactly on reinstallation.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before 3PM ship same business day from our climate-controlled warehouse.

Compatibility: Designed and tested for the Carrier C4850C48ZT105610 packaged unit. Always verify your existing transformer's VA rating and input/output voltages on the unit data plate or wiring diagram before ordering. If you're unsure of fitment, our HVAC parts specialists are available to confirm compatibility before you buy — no guesswork required.