Leak in basement ,

[Bobbydinpa]

So I’m working on a new to us prevost , I find that the plywood under the fresh water tank is completely rotted and gone and very wet ! Today I removed the fresh water tank and tested it , no leak 🤔 anyone know where else this could come from if not a holding tanks? No sign of any leakers above the tanks ??

[Fratto]

I am sure there are many sources including the door to the compartment and of course where the water ends up is not always where the leak is. Maybe someone has a good process for this, but I would assume that you would need to run all of the systems until you find the one that is leaking. With the tank out, you might be lucky enough to have access to much of the piping.

What year / type of bus do you have?

[Bobbydinpa]

Ours is a 1992 Monaco , the bus has been inside all winter,I just got it in the fall and looking everything over . I air tested the water system before putting any water and found it had not been winterized ! Or not done right if it was ? Since the plywood under the rubber is wet I am think I’ll remove the gray water bank next and see what I find? Fresh water tank is ok. I put treatment in the solid tank and I am not getting any smell good or bad so I hope it’s not that one!

[Fratto]

When you bring winterizing into the mix don't forget things like the washer, dishwasher, water heaters, ice maker, pumps etc. Could be coming from anywhere.

[Bobbydinpa]

Thanks Mark , I’ll let you know when I find it , I am going to remove the gray water tank and check it for a leak, I’ll need to take it out to replace the plywood anyway.

[georgiapeachinc]

Your coach is a few years older than mine so I assume it has the gray pipe throughout, but more on that in a second. I had something similar happen. I had water in the plumbing bay and it seemed to be coming from the fresh water tank because the plywood floor was wet around the tank. I discovered that the copper pipe leading up to the shower drain was leaking and water was traveling down the outside of the pipe and deposing on top of the fresh water tank and winding up on the bay floor. Long story short. The elbow running up the the drain floor had a hole in it. Corrosion I assume. I plugged it with Silicon and that was it! I pray it never has to be replaced. Tearing up the tile floor is the only alternative.

The other thing is this gray pipe. I just replaced several feet of it and the connections with Pex. I had another leak behind the shower due to tired gaskets in the connections. That leaked into the plumbing bay in two places. One of which was also on top of the fresh water tank. Keep your eyes open for leaks at the gray pipe connections.

[Bobbydinpa]

Thanks Chris , I have the aqua hot out ! It will be back from Co. Monday. I don’t see anything leaking down from above ? I only ran the shower a little , I have the hot and cold water connected now wit/h a by-pass at the aqua hot . I’m still going to have to remove the gray water tank to fix the floor , the plywood under it is also bad. I just hope it’s not the solid tank☹️but it seemed like it come from the back forward ? I have been in the plumbing and heating business for 45 years. Rule No. 1 it don’t have to make sense to be true ����

[Bobbydinpa]

[Bobbydinpa]

This is what the plywood looks like under the rubber!

[Fratto]

wow! you have a project on your hands :-)