OEM Carrier 40VA Control Transformer HT01BD236 for Model C48A205061

This OEM replacement control transformer (part number HT01BD236) is the factory-specified unit for the Carrier C48A205061 packaged unit. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, contactor coil, and control board. When this component fails, the entire control circuit goes dead — your thermostat becomes unresponsive, the system won't call for heating or cooling, and nothing turns on. A blown transformer is often caused by a short in the 24V secondary circuit, so always inspect low-voltage wiring before replacing.

• Specs: Input 120V AC | Output 24V AC | 40VA rated | OEM part number HT01BD236 | Factory-matched secondary impedance for stable control voltage
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA and impedance specifications. Generic transformers often run undersized VA ratings, causing voltage sag under load — which leads to erratic contactor chatter, nuisance lockouts, and premature control board failure.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: multimeter, flathead and Phillips screwdrivers, wire nuts or spade connectors. Always verify input and output voltages after installation before restoring the system to service.
• Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our NationalHVACParts.com warehouse.

Compatibility: Designed for the Carrier C48A205061 packaged unit. Verify transformer VA rating and primary/secondary voltages on your unit's wiring diagram or data plate before ordering. If your existing transformer shows signs of burning, discoloration, or a tripped secondary fuse, inspect the full 24V circuit for shorts prior to installation. Have questions about fitment? Our HVAC parts specialists verify compatibility before you buy — reach out before ordering.