The answer to 'pressure regulator constantly running' is that the pressure regulator is likely malfunctioning and needs to be repaired or replaced. A pressure regulator is a device installed on the main water supply line to a home that controls the water pressure entering the plumbing system. If the regulator is constantly running, it indicates an issue with the internal components that is causing it to work overtime to maintain the desired pressure.
Some common causes of a pressure regulator constantly running include a worn-out diaphragm, a stuck or faulty valve, or debris buildup inside the regulator. This can lead to fluctuations in water pressure throughout the home, as well as increased water usage and higher utility bills. In some cases, the entire pressure regulator may need to be replaced if the internal components cannot be repaired.