This is Turtle.
I was at the warehouse yesterday and was looking at some of the new hot water heaters on demand type , you know tankless types, and the rep. for the system brought up the Smelly water problem with these tankless hot water systems. He said there is a bacteria that will grow in a hot water system when set below
115ºF setting of the hot water system. He said to turn the hot water wide open for 5 minutes and run it to clear it out. This should clear it out to stop it.This can also happen on regular hot water tank systems and you can run the hot water high as it will go to clear it out too. There is such of a thing as Stinky hot water.
TURTLE