My water heater likes to start dripping out of the relief valve at the top side of the unit. If I put a bowl under it and pull the lever a bit and re-close it it stops dripping (the water is hot). So what is broke and what do I need to do to fix it. The old heater had a pipe attached to that valve and plumbed to the outside, so I don't know if it dripped or not. I keep meaning to plumb mine, but haven't got to it yet.