OEM Carrier 40VA Control Transformer for Model C4850C48AY06061

This OEM replacement transformer (part# HT01BD236) is the factory-specified control transformer for the Carrier C4850C48AY06061 packaged unit. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, contactor coil, and all low-voltage control circuit components. When this part fails, the entire control circuit goes dead — the thermostat goes blank, the contactor never pulls in, and the system will not respond to any call for cooling or heating. A failed transformer is often the first diagnosis when nothing in the system appears to work despite power being present at the unit.

• Specs: 40VA rated | 120V primary / 24V secondary | Class 2 transformer | OEM part number HT01BD236 | Factory-matched electrical rating
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Generic transformers may be under-rated in VA output, causing premature burnout under normal control circuit loads — particularly on systems with multiple low-voltage accessories.
• Install difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Confirm 24V output at secondary terminals after install before restoring system power. Label all wires before disconnecting.
• Warranty: 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Engineered specifically for the Carrier C4850C48AY06061 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering to confirm fitment. Our HVAC parts specialists are available to verify compatibility prior to purchase — no guesswork required.