Wet Furnace circuit Board

[In2b8r]

After a lot of head scratching I opted to tear into the furnace to figure our why I had no - anything. No Heat, no fan, no power.... I took off the furnace access cover on my 2017 3820FK and went to 'diagnosing' the problem. Well call me a genius but it only took about 2 seconds to recognize that the circuit board should not be partially submerged in water. We hadn't had rain in some time (we are a permanent site camper) and I hadn't washed the camper for several weeks. The water issue has been going on for some time as the red wire connected to the circuit board (I believe that is the power from the thermostat) was totally rusted off of the board. Now that I identified the problem my question is what is the solution? I can replace the board but will most likely have the same issue (?) Where is the water coming from (?) I can enhance the seal on the furnace cover door but I am not convinced that is where the water is coming in. On this camper model the Furnace sits directly below the Hot Water tank - I don't seem to have a leak, but wondering if on those cool nights I am having a condensation issue(?) Is this a known issue and what if anything can be done to prevent a reoccurrence of this situation (?)