OEM Carrier Control Transformer 40VA 208/230V to 24V for Model PY3GPAA36060AA

This OEM control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY3GPAA36060AA HVAC system. The transformer steps down 208/230V line voltage to the 24V low-voltage signal that powers your thermostat, control board, contactor coil, and all system safety circuits. When this transformer fails, the entire control circuit goes dark — the thermostat goes blank, the system stops responding to calls for heating or cooling, and no safety or fault codes can be generated. A failed transformer is often misdiagnosed as a control board failure, making correct identification critical before ordering additional parts.

• Specs: 40VA capacity | 208/230V primary input | 24V secondary output | 50/60 Hz | OEM part #HT01BD209 | Cross-references: HT01BD207, HT01CN232, 4000A46E07AE28, 9076-00
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact VA and impedance tolerances. Generic transformers may be undersized in sustained-load applications, causing voltage sag that triggers nuisance lockouts or damages connected control boards.
• Install difficulty: 3/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: multimeter (to verify 0V before touching wiring), flathead and Phillips screwdrivers, wire nuts or spade connectors. Always confirm primary voltage at your unit's data plate matches transformer input rating before energizing. Photograph all wiring before disconnecting.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse to the continental US.

Compatibility: Engineered for the Carrier PY3GPAA36060AA and other Carrier, Bryant, and Payne systems requiring a 40VA 208/230V-to-24V control transformer. Verify your unit's control circuit voltage on the data plate before ordering. Our fitment team is available to confirm compatibility — contact us before you buy if you have any questions.