OEM Carrier Control Transformer 40VA 208/240V to 24V — Model PY1PNB036060AAAA

This OEM Carrier transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY1PNB036060AAAA system. The control transformer steps down high-voltage line power (208/240V) to the 24V AC signal that powers your thermostat, control board, gas valve, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dark — the thermostat loses power, the system will not respond to any call for heating or cooling, and no error codes will display. If your system is completely unresponsive but your breaker is not tripped, a failed transformer is one of the first components to test with a multimeter.

• Specs: Input (Primary) Voltage: 208/240V | Output (Secondary) Voltage: 24V | Frequency: 50/60 Hz | Power Rating: 40VA | OEM Part Number: HT01BD209
• OEM vs Generic: This is the factory OEM part, built to exact Carrier specifications. Generic transformers may share the same VA rating but often use lower-grade core laminations, leading to heat buildup, voltage sag under load, and premature failure — potentially damaging the control board it powers.
• Install Difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output post-install). Photograph existing wire connections before removal. Always check for a shorted low-voltage wire that may have caused the original failure.
• Warranty: 1-year OEM manufacturer warranty. In stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier model PY1PNB036060AAAA. Also fits additional Carrier, Bryant, and Payne models that specify the HT01BD209 transformer — verify your unit's data plate voltage and VA requirements before ordering. Have a question about fitment? Our HVAC parts specialists verify compatibility before you buy — order with confidence.