How do I know if the S1-031-09170-000 is the right part for my system

specifically the AT-11-399 and AT-21-403 series

operating at 60 Hz

Use a multimeter to check the cold resistance across the lead wires

Engineered for universal refrigerant compatibility

Sterling 11J11R06778-002 Pressure Switch Els PW 17895 How do I know ifThe Sterling 11J11R06778 002 Pressure Switch is a critical safety and operational component designed for high performance HVAC system pressure monitoring. This OEM replacement part, which is technically identical to model J11R06778 002, ensures that your furnace or air handler operates within precise atmospheric parameters. Built to withstand the rigorous demands of industrial and commercial heating applications, this switch facilitates accurate