OEM Carrier 40VA Control Transformer 120V–24V for Model SUBCLR50HJ440684

This OEM Carrier transformer (part number HT01BD209) is the factory-specified replacement for the SUBCLR50HJ440684 unit. The transformer steps down 120V line voltage to the 24V control circuit voltage that powers your thermostat, contactor coils, and all low-voltage safety controls. When this component fails, the entire control circuit loses power — symptoms include a completely unresponsive thermostat, a system that won't turn on at all, or tripped low-voltage fuses with no apparent cause.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD209 | Factory-matched for SUBCLR50HJ440684
• OEM vs Generic: This OEM transformer is wound and rated to exact Carrier factory tolerances, ensuring stable 24V output under full control-circuit load. Off-brand transformers often under-deliver VA capacity, causing nuisance lockouts and premature contactor coil failure.
• Install difficulty: 2/5 — Shut off all power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label and photograph all low-voltage wiring before disconnecting. Verify 24V output at secondary terminals after installation before restoring full system power.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our stocked warehouse.

Compatibility: Direct OEM replacement for Carrier model SUBCLR50HJ440684. Always verify your unit's data plate voltage and VA requirements before ordering. Our HVAC parts specialists are available to confirm fitment — reach out before you order if you have any questions.