OEM Carrier Control Transformer 40VA 208/230–24V for Model PY2PNB042060AA

This genuine OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY2PNB042060AA packaged unit. The transformer steps down high-voltage line power (208/230V) to the 24V signal voltage that powers your thermostat, control board, gas valve, and all low-voltage system controls. When this transformer fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to calls for heating or cooling, and no fault codes will appear because the board itself has no power. If you're reading 0V on the secondary side of your transformer with correct line voltage at the primary, this part is almost certainly the cause.

• Specs: 208/230V Primary | 24V Secondary | 40VA Rating | 50/60 Hz | Direct OEM replacement for HT01BD209, supersedes HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: OEM transformers are wound and rated to exact factory VA tolerances, protecting sensitive control boards and gas valves from voltage fluctuation. Undersized or off-spec generic transformers can trip thermal protection or damage downstream electronics.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: multimeter, flathead and Phillips screwdrivers, needle-nose pliers. Always verify 0V at the primary terminals before touching wiring. Label all low-voltage wires before disconnecting.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier PY2PNB042060AA packaged unit. Verify your existing transformer's primary voltage (208/230V) and VA rating (40VA) against your unit's data plate before ordering. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you buy — just reach out before placing your order.