I have a well and a pressure tank. I lost water pressure last night and thought everything was frozen but it wasn't, however, the regulator was not engaged. I engaged the pressure regulator and the water was flowing through the pipes in the house. Now when the cold water is used in the house the water heater pulsates. What could be the cause of this?
Sounds like the pressure regulator is failing and needs to be replaced. Last time mine went, it would bang all the pipes after I used any water, hot or cold. Depending on your existing pressure regulator and the replacement you find, it may be as easy as unscrewing the old one and screwing on a new one. But more than likely, you'll need to cut the pipe and solder (assuming copper) a new connection or two.