OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3PNA018040NA

This OEM control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY3PNA018040NA system. The transformer steps down 208/240V line voltage to 24V to power the low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When it fails, the entire control circuit loses power: the thermostat goes blank, nothing responds, and the system shuts down completely with no error codes.

• Specs: 208/240V primary | 24V secondary | 40VA rated | 50/60 Hz | Factory-matched OEM tolerances | Also replaces HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances. Undersized or off-tolerance generic units can cause erratic low-voltage behavior, nuisance lockouts, or premature control board failure — especially under full 40VA load conditions.
• Install difficulty: 2/5 — Turn off all power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade terminals. Photograph existing wiring connections before disconnecting. Verify 24V output with a multimeter after installation before closing the panel.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier model PY3PNA018040NA. Also cross-references HT01BD207, HT01CN232, and 9076-00. Verify input voltage (208V or 240V) against your unit's data plate before ordering. Not sure it fits? Our team verifies fitment before you order — contact us and we'll confirm.