Problems with Tunze Osmolator 3155 ATO

mmw64 · Feb 1, 2018

My ATO now has two settings. Either it is adding water or the alarm is going off showing water level too high. I removed it and soaked it in vinegar and used a brush to clean. Set it back up and no change. Is there a way to replace the sensor without buying the whole thing again or does anyone have a fix for this problem?

nautical_nathaniel · Feb 1, 2018

Tunze sells replacement parts and also has a pretty solid warranty service, I would send them an email.

JoshH · Feb 1, 2018

Is it adding water over top of the sensor? How old is it?

Water Dog · Feb 1, 2018

@rvitko is the US Tunze rep. His service is second to none!

Cjud7982 · Feb 2, 2018

I just picked up a used osmolator system and it had some generic power supply and was acting goofy like yours. I cleaned everything like you did, there's no moving parts, aside from the high level float. I checked the power supply output voltage with a voltmeter and it was reading just shy of 2 volts. I replaced the power supply with a new one and cleaned the power connector female end on the 3155 unit. All works great now. Might be worth a shot

mmw64 · Feb 2, 2018

Water Dog said:
@rvitko is the US Tunze rep. His service is second to none!

How do I reach him?

mmw64 · Feb 2, 2018

Water Dog said:
@rvitko is the US Tunze rep. His service is second to none!

How do I reach him?

JoshH · Feb 2, 2018

Click on his name in waterdogs post and send a PM

BTW still curious on the age of your ATO

Water Dog · Feb 2, 2018

Roger’s direct email through TunzeUSA is [email protected]

mmw64 · Feb 3, 2018

JoshH said:
Click on his name in waterdogs post and send a PM

BTW still curious on the age of your ATO

Bought it in May 2016.

mmw64 · Feb 3, 2018

JoshH said:
Click on his name in waterdogs post and send a PM

BTW still curious on the age of your ATO

Bought it in May 2016.

mmw64 · Feb 3, 2018

JoshH said:
Is it adding water over top of the sensor? How old is it?

Bought it in May 2016.

Philt56 · Mar 6, 2018

I’m having problem too where sensor is completely submerged so it is not shutting off properly and topping off too often.

I sent an email through tunze website, will Roger receive it?

Water Dog · Mar 6, 2018

Yeah, he’ll get it. It’s not a siphon issue is it?

Philt56 · Mar 6, 2018

I just pm’ed just in case.

I don’t think it can be a siphon issue? I have a Red Sea reefer 425. The sensor is in the return pump section and the hose rises up to go through the opening at the top of the stands middle wall and then back down to reservoir on the far right side of the stand so I wouldn’t think a siphon would go uphill like that. I just moved the hose up in the clamp too so it’s not submerged.

When I tried it on my other tank awhile ago before setting up the Red Sea, I had seen the pump turn on while sensor was submerged.

Water Dog · Mar 6, 2018

Is the water level of the ATO reservoir higher than the end of the output hose of the ATO line that goes into the sump? If it is, then there’s your siphon.

Philt56 · Mar 6, 2018

Yeah if the reservoir is full, it would be close, but the output hose would have to be submerged toofor a siphon.

Also if the sensor is fully submerged, shouldn’t the “too high” led be lit? Mine has level lit. Or is that only lit when the float sensor is activated?

Water Dog · Mar 6, 2018

No, the end of the hose does not need to be submerged for a siphon to happen. If the end of the hose is lower than the water level in the ATO container, it will siphon. It’s following the laws of gravity. I’m pretty certain, that is your issue.

Philt56 · Mar 6, 2018

Thanks for helping on this.

Ok, get that, not sure what would it take for the siphon to break? Still water in reservoir. I would think siphon would go until nothing left?

Also still not sure if the level led should be lit if the sensor is completely underwater?

Water Dog · Mar 6, 2018

I have never really paid attention to the lights on my 3155 controller... sorry.

I think what’s happening is that when you first set the 3155 up, your ATO reservoir is full. Water evaporates from your sump telling the 3155 to trigger the ATO pump. It starts to fill your reservoir but overshoots your sensor because of the siphon. As it siphons, once the level in the reservoir is equal or lower than the level of the hose output, the siphon stops.