OEM Carrier Transformer 40VA 120V to 24V Control Circuit for Model C48A304052

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C48A304052 packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage required by your thermostat, control board, contactor coil, and all low-voltage safety controls. When this component fails, the entire control circuit goes dead — resulting in a system that appears completely unresponsive, with no thermostat display response and no relay or contactor activation. It is one of the first components to check when nothing in the system reacts to a call for heating or cooling.

• Specs: 40VA rating | 120V primary input | 24V secondary output | OEM part number HT01BD236 | Factory-matched construction for Carrier C48A304052 packaged units
• OEM vs Generic: This is a genuine OEM Carrier transformer built to exact VA and insulation class specifications. Generic transformers frequently underrate their VA capacity, causing thermal shutdowns and premature failure under normal HVAC control circuit loads.
• Install Difficulty: 2/5 — Disconnect all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 24V output after install). Label all low-voltage wires before removal. Check and replace any blown 3A control fuses while the panel is open.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our stocked warehouse.

Compatibility: Designed for the Carrier C48A304052 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltage from the data plate or old unit label before ordering to ensure correct fitment. Our HVAC parts specialists are available to confirm compatibility before you buy — orders placed before 3PM EST ship same day.