OEM Carrier 40VA Control Transformer HT01BD209 for Model PY3PNA024060AB

This OEM replacement control transformer (part number HT01BD209) is the factory-specified unit for the Carrier PY3PNA024060AB packaged HVAC system. The transformer steps down line voltage from 120V to the 24V AC signal that powers the entire low-voltage control circuit — including the thermostat, contactor coil, control board, and zone controls. When this transformer fails, the system goes completely dark at the thermostat and nothing operates. A shorted transformer will often trip or blow the control fuse as well.

• Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD209 | Factory-matched windings and mounting footprint for direct drop-in replacement
• OEM vs Generic: This OEM transformer is wound to exact Carrier factory specifications, ensuring precise 24V output under full load. Off-brand transformers frequently underperform at rated VA, causing erratic thermostat behavior, nuisance lockouts, and premature contactor coil failure.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after installation). Always label and photograph all low-voltage wiring before disconnecting terminals.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Fits Carrier model PY3PNA024060AB packaged HVAC unit. Verify transformer VA rating and primary/secondary voltages on your unit's data plate before ordering. Our fitment team is available to confirm compatibility prior to purchase — reach out before you order if you have any questions.