Tunze ato

[pirate]

So my year old tunze has decided that my tank is always needing filling. I've cleaned the eye, and it worked for 1 use the second time it just dies not quit filling. What do I check next? Or do I just go out and buy a new one? I would try and return it but it's had a hard life with me, the controller fell into my ato tank for a brief second and then the plug end fell into my sump while cleaning and after drying it out and cleaning inside of it it caught on fire for me.... So I chopped in a new power cord. So it's not eligible for warranty.
So I'm looking for what to try and clean next or buy a new one it worked like a charm till last night when it put in 4 gallons of water into my tank.