OEM Carrier Control Transformer 40VA 208/230V to 24V — Model PY3GNA042060NA (HT01BD209)

This genuine OEM control transformer is the factory-specified replacement for the Carrier PY3GNA042060NA packaged HVAC unit. The transformer steps down line voltage (208/230V) to the 24V control circuit voltage that powers your thermostat, control board, gas valve, and every other low-voltage component in the system. When this transformer fails, the entire control circuit goes dead — you'll see a blank thermostat, no response to calls for heat or cooling, and potentially a tripped or open secondary fuse. It is almost always the first component to check when nothing in the system responds.

• Specs: Primary voltage 208/230V | Secondary voltage 24V | Power rating 40VA | Frequency 50/60 Hz | OEM Part # HT01BD209 | Also replaces HT01BD207, HT01CN232, 9076-00
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact VA and voltage tolerances. Generic transformers often run hot under full control-circuit load, shortening lifespan and risking nuisance fuse trips on the 24V secondary.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, wire stripper, multimeter. Label or photograph all wire connections before removing the old transformer. Verify secondary output reads ~24–28V AC after installation before closing the panel.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Direct OEM replacement for Carrier model PY3GNA042060NA packaged units. Also compatible with other Carrier, Bryant, and Payne units specifying HT01BD207, HT01CN232, or 9076-00. Always verify your unit's data plate voltage requirements before ordering. Have a fitment question? Our HVAC parts specialists confirm compatibility before you buy — ships same day.