OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GNA024040NA

This OEM control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY3GNA024040NA HVAC system. The transformer steps down line voltage (208/240V) to the 24V signal that powers your thermostat, control board, and every low-voltage safety circuit in the unit. When this component fails, the entire control circuit goes dark — the result is a completely unresponsive system: a blank thermostat, no heating or cooling response, or a hard system lockout with no error codes.

• Specs: 40VA capacity | Primary: 208/240V, 50/60Hz | Secondary: 24V | Direct OEM replacement for HT01BD209 | Also replaces HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by the Carrier control board. Undersized or off-tolerance generic units can cause intermittent resets, nuisance trips on low-voltage safeties, or premature control board failure — choose OEM for a guaranteed fit.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label all wires or photograph connections before disconnecting the old transformer. Verify 24V output with a multimeter before reassembling panels.
• Warranty: 1-year OEM factory warranty included. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier PY3GNA024040NA HVAC system. This transformer is also a verified cross-reference for systems originally specifying HT01BD207, HT01CN232, or 9076-00. Always confirm primary voltage (208V or 240V) matches your unit's data plate before ordering. Our technical team is available to verify fitment prior to purchase — no guesswork required.