OEM Carrier Control Transformer 40VA 120V/24V for Model C4850C50ZG070200

This OEM replacement control transformer (part number HT01BD236) is the factory-specified unit for the Carrier C4850C50ZG070200 packaged system. The transformer steps down line voltage from 120V to the 24V AC required by the thermostat, control board, contactor coil, and all low-voltage control circuits. When this component fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any call for heating or cooling, and no diagnostic codes can be retrieved from the board. It is often the first component to inspect when absolutely nothing works.

• Specs: Input 120V AC | Output 24V AC | 40VA rating | OEM part number HT01BD236 | Factory-matched to Carrier C4850C50ZG070200 control circuit requirements
• OEM vs Generic: This OEM transformer is wound to exact VA and voltage tolerances. Generic alternatives frequently under-deliver on VA capacity, causing nuisance tripping, control board brownouts, and premature contactor coil failure — spending a few dollars more on OEM protects far more expensive downstream components.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Note all wire connections and label before removing the old transformer. Check for a blown 3A control fuse as the root cause before installing the new unit.
• Warranty: 1-year OEM factory warranty. Orders placed before 3 PM EST ship same business day from our warehouse.

Compatibility: Designed for the Carrier C4850C50ZG070200 packaged unit. Always verify your existing transformer's input/output voltage and VA rating against your unit's data plate before ordering. If you're unsure of fitment, our HVAC parts specialists will confirm compatibility before you buy — no guesswork required.