OEM Carrier 40VA Control Transformer for Model C4850C50Z2050200

This OEM control transformer (part# HT01BD236) is the factory-specified replacement for the Carrier C4850C50Z2050200 packaged unit. The transformer steps down 120V line voltage to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When it fails, the thermostat goes blank, the system stops responding to any call for heating or cooling, and nothing works. A failed transformer is often the first suspect when the system is completely unresponsive despite a live disconnect and proper line voltage at the unit.

• Specs: 40VA rating | 120V primary → 24V secondary | OEM part number HT01BD236 | Factory-matched output for reliable low-voltage circuit protection
• OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the C4850C50Z2050200. Generic units may be undersized in VA capacity, causing overheating, nuisance tripping of the internal fuse, or premature failure under normal system loads.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or terminal connectors. Always verify 0V at primary terminals with your meter before handling. Label all wires prior to disconnecting the old transformer.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C4850C50Z2050200 packaged unit. Verify transformer VA rating and primary/secondary voltage on your unit's data plate before ordering. If your low-voltage circuit has a short, replace the transformer only after locating and clearing the fault — otherwise the new unit will fail immediately. Our technical team is available to verify fitment and walk you through diagnostics before you order. Order today and get same-day shipping.