OEM Carrier Control Transformer 40VA 208/230V — HT01BD209 for Model PY3GNA036090AB

This OEM Carrier control transformer (part # HT01BD209) is the factory-specified replacement for the Carrier PY3GNA036090AB packaged unit. The transformer steps down line voltage (208/230V primary) to the 24V control circuit voltage that powers your thermostat, contactor coil, gas valve, and all low-voltage controls. When this transformer fails, nothing in the control system responds — the unit will not start, the thermostat goes dead, and no fault codes will display because the board itself loses power.

• Specs: 208/230V primary input | 24V secondary output | 40VA rated | 50/60 Hz | Class 2 control transformer | Replaces HT01BD207, HT01CN232, 9076-00
• OEM vs Generic: This genuine Carrier OEM part is wound to exact factory VA and voltage tolerances. Under-rated or off-brand transformers are a leading cause of repeated low-voltage fuse failures and nuisance lockouts — an OEM replacement eliminates that risk entirely.
• Install difficulty: 3/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: multimeter (to verify 24V output post-install), flathead and Phillips screwdrivers, wire strippers, needle-nose pliers. Always photograph existing wiring connections before removing the old unit. Check for a blown 3A or 5A low-voltage fuse — a shorted control wire may have caused the original failure.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: Engineered as a direct OEM replacement for Carrier PY3GNA036090AB packaged units. Verify your unit's data plate shows 208/230V supply voltage before ordering. Cross-references OEM part numbers HT01BD207, HT01CN232, and 4000A46E07AE28. Have questions about fit? Our HVAC parts specialists confirm compatibility before you order — contact us today and get your unit back online fast.