A:Answer Since it's apparent the Shark folks aren't going to help with a comment (phone number is great, but what about after hours or on a Sunday?), I'll share what's worked for me.
Anyway, if it's a sensor issue, then not sure what to tell you, but here's what has worked for me:
(1) there are three(?) pipes on the front end of the tank. When you have the tank removed and you're looking at the part/end that connects to the vacuum (the front of the tank), the pipes/tubes are on the Left side. I get a toothpick and gently poke all three, but I suspect the culprit is the Right-hand one because it has a check valve, and I depress the valve, causing a 1/16 of a tsp to leak out. I suspect this is sticking.
(2) I think it is sticking because I HAD been using 100% fluid. I now mix some water in with the fluid, so 50/50 mix. And that is very "about" because I add one to the tank and then the other, so it would be 30/70, dunno, but as long as there's some, or even a bunch of water because it think the solution/fluid is a bit thicker/stickier than water, so I want to thin it out to keep the check-valve from sticking.
Conclusion, I may be 100% wrong in my "fix," but it's worked for me.
