OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY4GNAA30060AA

This genuine OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY4GNAA30060AA packaged unit. The transformer steps down 208/240V line voltage to the 24V DC signal that powers your thermostat, control board, contactor coil, and every other low-voltage component in the system. When it fails, the entire control circuit goes dark — you'll see a blank thermostat display, no response to calls for heating or cooling, and potentially a tripped low-voltage fuse. Replacing this transformer is almost always the fastest and most cost-effective fix for a completely unresponsive unit.

• Specs: 40VA output | 208/240V primary | 24V secondary | 50/60 Hz rated | Replaces OEM part numbers HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: The OEM HT01BD209 is factory-wound to exact VA and voltage tolerances, ensuring the control board, contactor coil, and thermostat receive clean, stable 24V power. Generic substitutes may run slightly high or low on secondary voltage, causing nuisance lockouts or premature board failure.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire nuts or spade connectors, multimeter. Photograph all wiring connections before removing the old transformer. Secondary fuse should be inspected and replaced if blown.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Factory-matched for Carrier model PY4GNAA30060AA packaged HVAC unit. Also compatible with select Bryant and Payne models using the same 40VA 208/240V–24V transformer specification. Always verify your unit's data plate voltage before ordering. Have questions about fitment? Our HVAC parts team confirms compatibility before you buy — no guesswork.