I was hoping to find a leaking fitting but it seems that the water is coming from the bottom of the tank, although it is really hard to see into this area. Even with an aluminum tank do these ever corrode enough to leak...after 20 years?
Another weird observation.....I noticed what looked like engine coolant hoses (like what takes the engine coolant to the dash heater) and found in the original installation paper work that there is in fact 2 hoses that are routed to the motor of the coach. Not much in regards to explanation in the manual other than "hook up the coolant lines". Is referenced to as "heat exchange".