I have a residential boiler system in the house I bought. When I turned on the water supply to the boiler from the water system in the house, the T&P relief valve blew. I am assuming that this is because the water pressure in my household system (approx 70 psi) is too high for the boiler. The T&P relief valve has a 30 psi limit. Does anyone know what the component is that I need to put in line to lower the water pressure before it reaches the boiler? Any help would be appreciated!

A boiler water pressure regulator. They are usuallt set at 12 PSI from the factory.

Need to cut off hot water from the rest of the apt that are vacant,how do i do this w a oil boiler