Tunze 5017 ATO - Float Switch

Kar · Oct 18, 2016

Hi Guys,
I have Tunze 5017 as my ATO and I noticed this morning that the sensor stopped working, it is actually buzzing alarm sound even when all the water levels are correct. I would like to replace this sensor with float switch from Tunze. Could some help how would I replace it.

Thanks in advance

rvitko · Oct 18, 2016

The float switch is available as part 3152.300, however, that is a very old Osmolator, at least before 2008 and my advice would be to replace it as the float is not likely the problem. They are usually very durable as they are only a back up. More likely the pump or board is the cause.

wesleyclement85 · Oct 18, 2016

I here you should add extra silicone to the box when purchased before installing. They are great piece of equipment but tend to have a slight seal issue. (This is not my personal experience just information I got from multiple users when I was looking into one) so just passing that along hoping it helps

Kar · Oct 18, 2016

thanks guys, am looking to buy a new one and they are expensive :( is there any equipment that I can save from the current unit or all of it belongs to recycle ?

rvitko · Oct 18, 2016

The main problem is that so much has changed, if you just replace the controller it is 75% of what the whole unit costs. I am happy to have a look, maybe the pump and power supply can be saved, but since 2009 they come with much better magnet mounts. I would just wait for the Black Friday sales.

Regarding the seal, it is not a waterproof unit, it has no seal, the main point of water damage is people plugging in the power supply tip after it landed in water (unplugged and dropped in the sump or a puddle), no seal could solve this. We get accused of doing this deliberately and in a way that is correct, but not for a malicious reason. The board is deliberately designed to detect water damage and shut down showing an error code, if we did not do that, a short could cause a run on pump or defeat a safety. If you just place it where you would any other aquarium electronic (dry and away from splashes and spills) they will last a very long time with basic caution.