After replacing several of the cables and one valve, I decided to try the electric on the black water plumbing. Works great, for two years now, I will replace the grey water valves as they go bad. It was a easy install. The electric valve is very senesitive to the mounting bolt pressure. You may have to do several try and error sessions to get it right. I thought the bolts on mine were so loose that it would surely leak but not so.