Leak?????

[JOglesby]

Sometimes when we open the rv after a while we have water under the slide. We also have some swelling of the wood opposite of the slide. Like under the sink. But we never have standing water under the sink. We also don't see water on top of the slide. We have gotten some rather strong storms recently. I'm thinking maybe the water is getting inaround the water heater. It's the only penetration on that side and it's under the sink area. Has anyone seen this type of leak before?

I know it's not coming from the water heater as I drained it and we still saw this

 

[Mikendebbie]

JOGlesby - for every question you should include your RV make, model and year. Fortunately you included this info on your profile page so I looked up your floor plan (screen shot below). The experts in this forum can offer more help if they know which RV you own. 2021 Keystone Bullet 290BHS.

It definitely sounds like a plumbing leak - not a slide leak.
In the floor plan below - you are only finding moisture at location “D” under the sink?
You stated that you “drained the water heater”…did you also drain the whole plumbing system using the low water point drains?
How long has it been that you have noticed the dampness and soft floor?
If you had drained the plumbing system/water heater and the moisture showed up (say) after a rain, then perhaps it could be a leak from the slide.