OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GPAA36090AA

This OEM control transformer (part number HT01BD209) is the factory-specified replacement for the Carrier PY3GPAA36090AA HVAC system. The transformer steps down line voltage from 208/240V to a stable 24V AC output that powers your thermostat, control board, contactors, and all low-voltage control circuitry. When this transformer fails, the entire control system goes dark — the thermostat becomes unresponsive, the system won't call for heating or cooling, and no fault codes are generated because the board itself has no power. Replacing it with a factory-matched OEM unit restores reliable control voltage and full system operation.

• Specs: 208/240V Primary | 24V Secondary | 40VA rated | 50/60Hz | Class 2 control transformer | Direct OEM replacement for HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: OEM transformers are wound to exact factory VA and voltage tolerances, protecting sensitive control boards from voltage fluctuations. Generic units may deliver inconsistent output voltage, risking nuisance lockouts or premature board failure.
• Install difficulty: 2/5 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after installation). Photograph and label all wiring connections prior to removal.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier PY3GPAA36090AA HVAC system. Also replaces superseded Carrier part numbers HT01BD207, HT01CN232, and 9076-00. Always verify primary voltage on your unit's data plate matches 208/240V before ordering. Our fitment team is available to confirm compatibility before you buy.