My water heater has a little valve on the outside of the tank near the top. This valve is slowly dripping a little water on the floor. It’s not doing any damage but it irritates me. There is a pipe thread on it and it goes nowhere. Do I need this? Can I purchase a plug and stop the leak? I assume that the pipe thread is to have a pipe piped into it. Am I to hook a hose into it? What is it for?
That valve is called a relief valve. A relief valve is designed to stay closed. In the event that the pressure would increase in the tank of the heater due to overheating, the relief valve would relieve pressure in the tank and blow off. You cannot plug that off because that would leave the heater in an unsafe state and have the potential of the heater blowing up and someone could get hurt. If it leaks, it should be changed. State code says to have a piece of rigid pipe screwed in it and also terminate 1-6 inches from the floor. If it were to blow off under extreme heat and pressure with no pipe screwed into it, you wouldn’t have the ability to approach the heater to shut it down. State code also says no valves are allowed downstream of the relief valve. Please call and we will replace the leaky valve.
Wes Rosenberg, Owner/Master Plumber