So I now have a third failed Tunze Nano unit. They always fail the same way -- they start filling over top of the float switch, not tripping off until they hit the time limit. Yes, the float switch is floating freely and yes I can *manually* trip the ATO by moving the float with my fingers. (Just for clarity, the Nano unit, Model 3152, does not have an electric eye -- only a float switch). They seem last a year, or two. Is there a better solution out there now or do I just buy another Tunze Nano and make my parts drawer a little richer?