OEM Carrier Control Transformer 208/240V to 24V 40VA — HT01BD209 for Model PY3PNA060090NB

The Carrier HT01BD209 is the factory-specified OEM control transformer for the PY3PNA060090NB packaged unit. This transformer steps down the incoming 208/240V line voltage to the 24V AC control signal that powers your thermostat circuit, gas valve, contactor coil, and all low-voltage control logic. When this transformer fails, your entire control circuit goes dark — the thermostat loses communication, the system refuses to start, and no heating or cooling function responds. A bad transformer is often misdiagnosed as a failed control board, making correct identification critical before ordering expensive downstream components.

• Specs: Input Voltage: 208/240V | Output Voltage: 24V | Frequency: 50/60Hz | Power Rating: 40VA | OEM Part #: HT01BD209
• OEM vs Generic: This is the genuine Carrier OEM transformer, wound and insulated to exact factory tolerances. Generic transformers can deliver inconsistent 24V output under load, causing intermittent lockouts, nuisance trips, and premature failure of downstream components like contactors and control boards.
• Install Difficulty: 2/5 — Shut off all power at the disconnect and breaker before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper, and needle-nose pliers. Photograph all wiring connections before disconnecting. Verify 24V output with a multimeter after installation before restoring full power.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered as the direct OEM replacement for the Carrier PY3PNA060090NB packaged unit. Verify your unit's data plate for 208/240V primary input and 24V/40VA secondary rating before ordering. Not sure it's the right part? Our HVAC parts specialists verify fitment before you buy — reach out before placing your order.