with yellow indicators for tenths and hundredths

Is this the correct spring for a 2 PSI line pressure system

Precise Pressure Regulation: Maintains optimal head pressure by modulating fan speed

This 1-1/2 inch bronze boiler pressure relief valve is factory-set at 30 PSI

Venstar VST3900 Thermostat 322027-701 with yellow indicators for tenthsThe Venstar VST3900 is an enterprise grade programmable thermostat designed for high performance multi stage HVAC systems. As the direct replacement for P374 1500 and P374 1900 legacy units, it offers backward compatibility while upgrading system control. This 7 day programmable digital thermostat supports 3 heat and 2 cool stages, making it compatible with gas electric or heat pump systems, including those with auxiliary heat. Field technicians value