OEM Carrier Control Transformer 40VA 120V/24V for Model C48A302052

This OEM replacement transformer (part number HT01BD236) is the factory-specified step-down transformer for the Carrier C48A302052 packaged unit. The transformer converts 120V line voltage down to the 24V signal that powers your thermostat, control board, contactor coil, and all low-voltage control circuits. When this component fails, the entire control system goes dark — your thermostat shows no response, the unit won't call for heating or cooling, and nothing happens when you adjust the setpoint. A failed transformer is often the first suspect when a system appears completely dead with no error codes.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory-matched output for stable low-voltage control circuits
• OEM vs Generic: OEM transformers are wound to exact VA ratings and insulation class specifications for this unit. Undersized or off-brand transformers can drop voltage under load, causing intermittent lockouts and premature control board failure — costing far more than the part itself.
• Install difficulty: 2/5 — Disconnect power at the disconnect box and verify zero voltage with a multimeter before proceeding. Tools needed: flathead and Phillips screwdriver, multimeter, wire nuts or spade terminals. Label all low-voltage wires before disconnecting. Check for a blown fuse on the control board as the root cause before replacing the transformer.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed as the direct OEM replacement for Carrier C48A302052 packaged units. Always verify the VA rating and primary/secondary voltages on your unit's wiring diagram or data plate before ordering. Our fitment team is available to confirm compatibility before you buy — order with confidence and get your system back online fast.