Tunze 3155 ATO troubles

[skijumpersc]

I bought a used tank a couple days ago that came with a Tunze 3155 ATO. When I first set it up on my tank its been having trouble priming. I cleaned it with vinegar and tried turning it upside down and shaking it to get any air out, but it still had the same issue. I found if I opened the controller up and turned the pressure up I can get it to prime, but now I'm having the issue where it fills past the optical sensor and doesn't stop until it hits the float. 

I have it set up in the return pump chamber of an RSM 130. 
 

Has anyone had similar issues?

[Polarcollision]

Roger at Tunze USA offers amazing customer support and can troubleshoot your ATO with you. I get the impression that he's the primary reason Tunze has such a good reputation. I had a similar issue with mine after years of working flawlessly. He went through some basic troubleshooting steps to rule out typical issues and then had me mail it off to him for a fix. That worked for a while and then it acted up again so he sold me a new unit at a fair prorated discount. The new unit started acting up, but I eventually traced it down to microbubbles from the new Tunze skimmer floating over to the optical sensor which the sensor reads as a low water level. A little filter floss in the skimmer chamber appears to have stopped microbubbles from escaping and also fixed the overfilling in the middle of the night issue.

 

When I had a priming issue, Roger mailed out a replacement pump. They're also available online for pretty cheap. That seemed to help. Because the tank you have is a small volume of water, the increased speed of water delivery that happens from increasing the water pressure can sometimes overfill the tank when the pump reprimes after being turned off. there's a set time that it auto pumps after being turned off. In my 24 g tank, the higher pressure setting will overfill my tank. Can you set the pressure dial to somewhere between the high and low setting and still get it to prime? Also, I think there's a max head height for the pumps. Mine moves water around 3.5-4 feet vertical. He also had me check the tubing from pump to tank. If it's not original there's a chance it's too wide diameter for the pump to move vertically.

[StevieT]

You could also try putting a buffer between the rear mounted magnet.  Because the magnet is so strong depending on the glass thickness it can interfere with the magnet in the float.  The recommended buffer is a beer coozie

 

Cut a square:  Magnet>coozie piece> glass

[Polarcollision]

5 minutes ago, StevieT said:

You could also try putting a buffer between the rear mounted magnet.  Because the magnet is so strong depending on the glass thickness it can interfere with the magnet in the float.  The recommended buffer is a beer coozie

 

Cut a square:  Magnet>coozie piece> glass

Hey Stevie, I just went to check my 3155 to be sure. There's no magnet involved with the float control. It's just the optical sensor and a plastic backup float shutoff held in place by the magnet. Most likely don't want that magnet weaker so it stays firmly in place.

[StevieT]

2 minutes ago, Polarcollision said:

Hey Stevie, I just went to check my 3155 to be sure. There's no magnet involved with the float control. It's just the optical sensor and a plastic backup float shutoff held in place by the magnet. Most likely don't want that magnet weaker so it stays firmly in place.

That is true on the 3155.  The backup float has a very small magnet it in through, but the optical should register first.

 

Reaching out to Roger is a great idea.  He provides the best support and knows these products very well.

[Polarcollision]

I'm looking at the float again and can't find even a tiny magnet on the float. Where is it?

 

P.S. With all the things that can fail on a reef, your media baskets are still going strong 4 years later. 🙂

[StevieT]

4 hours ago, Polarcollision said:

I'm looking at the float again and can't find even a tiny magnet on the float. Where is it?

 

P.S. With all the things that can fail on a reef, your media baskets are still going strong 4 years later. 🙂

Nice.  No moving parts no electricity lasts forever. 

 

I think it's in the tube the float rides up and down on. The coozie advice is something I have on file from Roger.