Nano Osmolator Pump Not Pumping

[SunfishFun]

Over the weekend it seems our Nano Osmolator stopped pumping after a few months of service to our classroom frag tank. While troubleshooting, I unplugged and plugged it in and two times it pumped in a tiny bit of water as usual, but after that it stopped working altogether and does not respond in any way. I do not think trapped air is the problem. I checked the wires at the connectors and they look fine. I read that people test it with a 9V battery - do I just disconnect the wires and attach them to the terminals? (Good for me to know how to do this because we use the 3155 Osmolator on our big reef tank and have another Nano on the way for a new clownfish tank.)

Also, I think the max head is stated at 3.5m for the pump. We have about 1-1.25m between the reservoir and topoff input levels. Let me know if it should be lower for some reason.
Thanks,
Maureen

 

[rvitko]

Hi Maureen,

It sounds like almost for sure the pump is the issue, the battery test is of limited use as we only get an answer if the battery does not run the pump. You just touch the pump wires (blue and brown) to the terminals of the battery, polarity does not matter. The pump can work with the battery and yet not work with the controller because the controller will cut power to the pump if it needs too much power. I am reasonably sure a new pump will solve this, you could also try the Osmolator pump you have, that would be a more certain test to try a known working pump. I can send a new pump if you need, just let me know.

 

[SunfishFun]

I received another Nano Osmolator for a different tank today, so I swapped the pumps and the problem persists. It seems like a problem somewhere with the power transfer. Neither pump goes on when I unplug and replug. I also tested it by making the water level drop below the sensor and a couple of times both pumps would pump topoff water in, but usually neither pump works. Was planning to examine, clean the sensor tomorrow, but since it does not go on when plugged in I was wondering if there is something I should check in the controller box.

 

[rvitko]

You could check for any water damage, make sure the float is plugged in and check for any burned components on the board. Usually though the problem is invisible, if you send it in I will get it resolved.

 

[SunfishFun]

I never sent it in because the controller looked okay visually and then I cleaned the sensor, which seemed to fix the problem. However, over a few days of vacation it stopped topping off again. I couldn't see a problem and switched in a new Nano Osmolator pump with the controller and sensor (waiting for a new tank). I thought it was working but after a couple of tests of removing water so the float falls and triggers the water addition, it stopped working again. I read the whole manual and cannot locate the problem, but it seems like operator error if I have the same problem with two units!
Don't know if this matters: Float sensor is installed in the little return compartment of an all-in-one box along with the little return pump, the pump cord running next to the magnet, and the ATO freshwater entering this chamber. Any problem with this setup?

 

[SunfishFun]

You know, I just read an earlier thread about higher evaporation in winter. I noticed this on my big tank - classroom is cold and dry. I was surprised to read in your response how long it can take to topoff what I thought was a small amount of water but may have underestimated the amount. I brought home the extra osmolator and will try to set it up in a bucket and see if maybe the pump is shutting off after the maximum refill time.

 

[rvitko]

The safety on the nano is a timer, it starts counting down when the float is switched on. The default setting is for under 25 gallons and will shut off the pump after 1 min 48 seconds. There is an optional 3 minute setting explained on pages 26-29 of the manual, this is for 25-55 gallons. If the timer is the cause, the pump will pulse one brief twitch every 20 seconds for a while as an alarm to let you know it timed out.