Thank you! Never would have found that float valve. It's amazing how I can get obsessed with stuff like this. I have now scoured the net and there isn't a reasonably price evaporative or ultrasonic humidifier with autofill capability. There was one, https://www.alzashop.com/bionaire-airtek-pcmh45-dw-d379438.htm, now discontinued. Dumb question: If you connected the water line without the float, with the saddle valve turned down low to reduce the pressure, would it still leak? Would it overflow? Also curious if your issue is simply an issue attributable to that unit. I think I am going to go with an evaporative model, and may try to screw around with setting up an autofill. https://www.amazon.com/dp/B0012KO7DS/?tag=skimlinks_replacement-20 This has 2 tanks, so I don't know if setting a waterline to only one would do the trick. I have to imagine that the system draws from only one tank, and then the other?