Originally Posted by mtnman
I thought that it may be that but was not sure, it looks a lot like a water heater pressure valve. I am not going to put that back in the coach, it was leaking.
well...that's what it is supposed to do...IF there's too much pressure somewhere. might be functioning normally. or it could be broken. just leaving the system pressurized, with the hot water heater on, and not opening a tap for some time (like you might do if you were to turn on the water heater while the rig is in your back yard, and then forget to turn it off, and it sits there running for days or weeks) could cause enough pressure to build in the lines, and trigger this device.