indicating refrigerant shortage or liquid line restrictions

Is this switch suitable for both Natural Gas and Propane Raypak heaters

How do I identify the correct Maxitrol spring for my regulator

What is the purpose of the 12A39 vent limiter in this model

Johnson Controls A70KA-1 Control Els PW 29614 indicating refrigerant shortage or liquidThe Johnson Controls A70KA 1 Control is a heavy duty, high limit temperature controller designed for critical HVACR safety applications. This remote bulb temperature control operates within a setpoint range of 100F to 170F, specifically engineered to open the main circuit upon a temperature rise. Featuring a 4 wire, 2 circuit contact block, the A70KA 1 (identical to the A70KA 1C) provides two isolated sets of contacts: as the main LINE M2 contacts