You need to be a little more specific. A regulator is designed to allow the flow of gas, air, or water to a specific pressure or volume through an orifice into whatever it is you are trying to fill or use it for. Disconnect the output side of the regulator. It can be shut off to stop the flow by turning it clockwise until it seats and prevents ( in your case, water, ) from flowing out. Counter-clockwise opens it up. If doing this doesnt stop the water from going through the regulator, then the regulator is faulty. I assume you dont have a needle guage to use for setting the pressure you want to use. Get one! Hope this helps.