ATO 3155 pump

[newbie2014]

Hi, to all Tunze ATO experts here.

I purchased a used Osmolator 3155 about three weeks ago. It has worked wonderfully until the last few days. The problem is the pump cannot pump the water over the rim of my DT which is only about 4ft high. So, the pump would turn on for the few seconds, retry (pumping) for 2-3 times, then it just stops. And the yellow light stays on. While the pump is on, I can see the water creeping up slowly to about a few inches below the tank rim then it stops moving. The reservoir/pump sits directly below the tank, and there is no slack in the water tubing.

Now, the tube that I use is a generic 1/2" ID which I bought from HD. The original black tube was cut too short (by the previous owner) for me to reuse. The tube fits nicely, but not as tight fitting as the original tube does. Since the pump is completely submerged in water, I didn't think the slightly loose fitting would be the issue, and it had worked fine for the last few weeks. But, could it be?

Also, is it possible to open the pump to see if something got stuck and clean the inside?

I appreciate any ideas and suggestions.

PS. According the previous owner's tank Build Thread, he bought it in May 2014.

 

[rvitko]

1/2" is quite large, the original tubing is 4mm ID which is less than 1/4", it inserts inside the fitting not over it. I think this is severely limiting the head capacity. It could also be the previous user opened the controller and turned down the pump speed. Any Osmo made after 2012 has the pump speed adjustment. The pumps are a sealed unit and cannot be opened or repaired. The original tubing is available on Amazon, 5000.390 is 9ft, 5000.380 is a bit over 30ft.

 

[newbie2014]

1/2" is quite large, the original tubing is 4mm ID which is less than 1/4", it inserts inside the fitting not over it. I think this is severely limiting the head capacity. It could also be the previous user opened the controller and turned down the pump speed. Any Osmo made after 2012 has the pump speed adjustment. The pumps are a sealed unit and cannot be opened or repaired. The original tubing is available on Amazon, 5000.390 is 9ft, 5000.380 is a bit over 30ft.

Thank you for replying. You're right 1/2" ID is too big. I meant to say 1/4". It's the same tube typically used for air pumps. It fits inside just like the original tube, just not as snug as the original. I've read other people also have used it, and it worked for me for a couple of days. I may have to visit Amazon for that part so I can narrow down the problem.

I had opened the controller hoping to be able to up the pump speed, but I didn't the dial. I think the previous owner may have bought a used unit.

Thanks again

 

[rvitko]

They started adding the speed control in Nov 2011, so we would have to assume it is older than that and you may just need a new pump in that case. Another thing that can happen with underside tubing is it is too far and actually making contact with the impeller. The correct size tubing fits very tight and it usually only goes in 1/4-1/2".

 

[newbie2014]

Thanks again for your input. I'll get the original tube. I also have a (older) spare pump that I can use.