OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GNAA42060NA

This OEM control transformer (part number HT01BD209) is the factory-specified replacement for the Carrier PY3GNAA42060NA packaged unit. The transformer steps down 208/240V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and every other low-voltage component in the system. When this transformer fails, the entire control circuit goes dark — the thermostat gets no power, the system will not respond to any call for heating or cooling, and no diagnostic fault codes will appear. A blown fuse on the secondary side is often the first clue; a dead transformer is frequently the root cause.

• Specs: 208/240V primary | 24V secondary | 40VA capacity | 50/60 Hz | Replaces OEM part numbers HT01BD207 and HT01CN232
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and impedance specs. Generic substitutes may be under-rated for inrush current, leading to nuisance fuse trips or premature failure under load.
• Install difficulty: 2/5 — Shut off all power at the disconnect and verify with a meter before touching wiring. Label or photograph all 24V secondary wiring before disconnecting. Tools needed: flathead and Phillips screwdrivers, wire nuts or spade connectors, multimeter. Always replace the secondary fuse if one is present.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier PY3GNAA42060NA packaged unit. Cross-references include OEM part numbers HT01BD207 and HT01CN232 — verify your existing part number on the transformer label before ordering to confirm fitment. Questions about compatibility? Our HVAC parts specialists confirm fit before you buy.