OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GNAA60115AA

This OEM control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY3GNAA60115AA packaged unit. The transformer steps down line-voltage power (208/240V) to the 24V used by the unit's thermostat, control board, contactor coil, and all low-voltage safety circuits. When it fails, the entire control circuit goes dark — the thermostat becomes unresponsive, contactors won't energize, and the system will not heat or cool under any call. A failed transformer is often caused by a shorted low-voltage wire or a failed component drawing excessive current; always inspect the secondary circuit before installing a replacement.

• Specs: 40VA rating | 208/240V primary input | 24V secondary output | 50/60 Hz | OEM part number HT01BD209 | Also replaces HT01BD207, HT01CN232, 9076-00
• OEM vs Generic: This genuine Carrier OEM transformer is wound to exact VA and voltage tolerances. Generic units frequently under-deliver VA capacity, causing nuisance tripping and premature failure of downstream control boards.
• Install difficulty: 2/5 — Shut off all power to the unit at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (to test secondary for shorts before energizing). Photo all wiring connections prior to removal. Check for shorted low-voltage wiring before powering up the new transformer.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier model PY3GNAA60115AA. Verify primary voltage (208V or 240V) matches your unit's supply voltage shown on the data plate before ordering. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you buy — contact us today and we'll ship it out the same day.