How do I verify if the 4520-0015-000 is failing

Durability: Built to withstand the thermal cycling typical of high-efficiency gas furnaces

the B1370920 furnace limit switch automatically closes

and 36G series valves

This 36-inch

MARS 33242 Relay How do I verify ifThe MARS 33242 Relay is a specialized 24V SPST NO time delay relay engineered for precise control in HVACR systems. As a veteran grade HVAC compressor time delay solution, this component utilizes a solid state PTC (Positive Temperature Coefficient) device. When current flows through the control circuit, the PTC element heats an internal snap acting disc, facilitating a reliable make or break contact transition. This thermal time delay relay is