We have Sensa Tank installed in our coach, which, for the past 6 years has worked fine. Lately, the grey tank has decided to be unreliable. After emptying the tank, it will read 1/4 full. In the past, I had discovered sensors that came loose on the fresh water tank, and since they were easy to get to, they were easy to reattach.<br/>I am not sure why the grey isn't working...