We had a new electric hot water heater installed recently. Everything was fine untill after a couple days when we noticed water in the catch pan. The plumber came and replaced the relief valve. A couple days later, leaking again. This time the plumber replaced the regulator. Another couple days and, yes, it leaks. This has been an ongoing problem even with the old heater, but we did not know it was leaking as the pipe was ran through the floor and into the crawl space below the house. This is now the third time in 5 years the regulator has been replaced. I have been told that the pressure can build up when other homes on the street are not using much water, thus causing the leaky valve. If this is true, is there something that the local water dept. can or should do at the meter the remedy this?

MSSP is giving you good advice, you need a thermal expansion tank.
If the regulator you are speaking of is a pressure regulator then you need the tank. The regulator also acts as a check valve. When the water in the tank is heated it expands, causing the pressure to build. This is why the relief valve is opening. It is doing it's job to protect the tank from excess pressure. Looks like you have been replacing regulators that there was nothing wrong with.

Three hundred PSI is extremely high, I don't think I have ever seen a city main carry that much pressure to a residential home. Most pressure reducing valves are not rated to handle that much pressure. Some are rated for a maximum of 300 PSI but there is a big difference between maximum and working pressure. I think the reason for his leak in the crawl space is because that is were the relief valve is piped to.

MORE NEWS