OEM Carrier Control Transformer 40VA 208/240V to 24V for Model SUBCLR50HJ440086

This OEM Carrier control transformer (part number HT01BD209) is the factory-specified replacement for the Carrier SUBCLR50HJ440086. The transformer is the heartbeat of your HVAC system's low-voltage control circuit — it steps down 208/240V line voltage to a steady 24V output that powers your thermostat, control board, contactor coil, and all safety circuits. When a transformer fails, the entire control system goes dark: the thermostat becomes unresponsive, the system won't energize, and no heating or cooling cycle can begin. Replacing a failed transformer promptly avoids misdiagnosis of more expensive components like the control board.

• Specs: 40VA capacity | 208/240V primary input | 24V secondary output | 50/60 Hz | Class 2 control transformer | Replaces legacy part numbers HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: The OEM HT01BD209 is wound to Carrier's exact VA rating and insulation class. Generic transformers may be under-rated for inrush current loads, causing nuisance trips or premature failure — especially in systems with multiple low-voltage loads on a single transformer.
• Install difficulty: 2/5 — Always disconnect power at the disconnect box before servicing. Tools needed: multimeter (to confirm primary voltage and verify 24V output after install), flathead and Phillips screwdrivers, wire nuts or spade connectors. Photograph all wiring before removal. Check for a shorted low-voltage load (e.g., a stuck contactor coil) before installing the new transformer, as a downstream short will destroy a new unit immediately.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier model SUBCLR50HJ440086. Verify your unit's data plate confirms 208/240V primary supply before ordering. Need fitment help? Our HVAC parts specialists confirm compatibility before you buy — order with confidence and get back to comfort fast.