How do I confirm if this SPDT limit switch is compatible with my York unit

Does the MARS 12201 work for both 50Hz and 60Hz systems

an open circuit during a cool state typically indicates a failed component

The Aaon P51900 follows the standard 8-pin blade layout

Lennox 84L00 Limit Switch How do I confirm ifThe Lennox 84L00 Limit Switch is a critical OEM replacement part designed for high precision thermal monitoring in residential and commercial furnaces. Engineered as a 130 160F AUTO limit switch, this SPST (Single Pole Single Throw) control features a 3 inch stilt insertion to provide accurate sensing within the heat exchanger airflow. This component is identical to part number 84L0001 and serves as a direct Lennox furnace high limit replacement,