I have just loaded the van in preperation for the trip to Peterborough and as I filled the water tank I forgot it, and it filled to the top and overflowed from the neck. Oh well so I dropped a bit out of the drain tap to bring it down a bit. It still read 100%, Today I went back in and did a check on the system to see the battery charge and water level again, It read 75% then dropped to 50% now it is empty and the flashing light is warning me that it is empty, but it isn't empty I have lost none and there is no leak neither have I used any. No doubt the gauge is now wafty, and I cannot tell how much is in there now. How does it work is it a float and resistor system or an electronic resistance dip tube type. I was wondering if a good bouncy trip along our local roads would fix it or is it a warranty fix. It is a Hymer MLI580. Any one else have this ? Have the local ner-do-wells siphoned off my water thinking they were getting my diesel.