Pressure regulator valve broke (easy fix) 

Part number for the old one LF N45B M1 and New one.
When removing the pressure regulator valve close the main line to the house and once that’s done release the pressure by opening a Fossett to take all the water out and then follow by removing the water pressure regulator valve remember to open the top one first then the bottom one then When installing the bottom one first then the top one hope this video helps.