OEM Carrier 40VA Control Transformer HT01BD236 for Model C48A202561

This OEM control transformer (part number HT01BD236) is the factory-specified replacement for the Carrier C48A202561 packaged unit. The transformer steps down line voltage (120V) to the 24V AC control circuit voltage that powers your thermostat, contactor coils, gas valve, and control board. When the transformer fails — due to a shorted control wire, overloaded circuit, or age — the entire control circuit goes dead: the thermostat displays nothing, the system won't respond to any commands, and nothing turns on.

• Specs: 40VA rating | 120V primary | 24V secondary | Class 2 control circuit transformer | Factory-matched OEM tolerances for stable low-voltage output
• OEM vs Generic: The OEM HT01BD236 transformer is wound to Carrier's exact VA and impedance specifications. Generic transformers rated at 40VA often run hot under sustained load, tripping internal thermal cutoffs prematurely and risking repeat failures on the same service call.
• Install difficulty: 2/5 — Disconnect power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Confirm 24V output after installation before reconnecting the control circuit. Check for shorted low-voltage wiring that may have caused the original failure.
• Warranty: 1-year OEM factory warranty. Orders placed by 3 PM ship same business day from our warehouse.

Compatibility: Fits Carrier model C48A202561 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit's data plate or wiring diagram before ordering. If you're unsure of fitment, our HVAC parts specialists confirm compatibility before you buy — no guesswork.