Tunze osmolator nano 3152 not working intermittently

lifer

New member
Hi Tunze.

Would apreciate some help diagnosing a problem I'm experiencing with my Tunze ATO. I have it connected to a biocube 29g with a 5g resivour. I'm finding lately that I will check the tank and my water level in the back sump is low. If I unplug and plug back in the power supply, the pump will turn on and fill to the float hieght. Most of the time, it works as intended, however, intermittently, it will let the water level drop and I would have to unplug and plug to reset.
I clean the float valve monthly in a 50/50 vinegar water soLuton. Why is this happening? and how do I fix it? I will be on vacation next month and I want some security that my ATO will work properly. Thanks
 

rvitko

RC Sponsor
RC Sponsor
One possibility is the evaporation rate has increased which is common in winter with cold dry air and heaters running and you need to extend the safety timer as explained on pages 21-29. The other possibility is the pump is faulty, a faulty pump will stop after a short run time. You can verify the cause by setting up a dry test run, this could be just raising the float out of the water and disconnecting the top off hose from the pump. Time the pump, if it runs 1 min 48 seconds, the safety timer needs to be extended, if it runs less, usually under 20 seconds and then stops, a bad pump is the cause.
 

lifer

New member
One possibility is the evaporation rate has increased which is common in winter with cold dry air and heaters running and you need to extend the safety timer as explained on pages 21-29. The other possibility is the pump is faulty, a faulty pump will stop after a short run time. You can verify the cause by setting up a dry test run, this could be just raising the float out of the water and disconnecting the top off hose from the pump. Time the pump, if it runs 1 min 48 seconds, the safety timer needs to be extended, if it runs less, usually under 20 seconds and then stops, a bad pump is the cause.

Thanks Roger. I'll try that. You're right that the evaporation rate has increased. I am having to fill my ato container more frequently. I suspect a faulty pump because the biocube sump is relatively small, so when it evaporates, it only replaces a small amount of water. It is just comingon more frequently. Every now and again, I'll find the water level really low and I will reset with the plug and it will replenish to normal.
 

rvitko

RC Sponsor
RC Sponsor
A bad pump will fail in a very short run, usually under 20 seconds. The controller detects the overload and cuts the power to the pump. Even at a full 1 min 48 seconds the fill is limited to a quart to about a third gallon depending on head pressure, it is designed so even if the float sticks or fails it won't flood a nano.
 

Ceaver6040

New member
I'm having a related problem with my Tunze nano, and I noticed Roger was active on this thread recently, so I hope I'm not hijacking too much.

Just recently, after plugging my unit back in, the pump only runs for a second, then stops. Unplugging and plugging back in doesn't help. Interestingly, it will run dry, outside of the water tank. But once it's in water, it stops. Upside down, right side up, it runs dry, but won't run underwater. It's only ever been in RO water and has worked fine for several months.

Any ideas or suggestions about what may be wrong? Any help is greatly appreciated.

Thanks!
Greg
 

NanoReefer53

New member
Subscribing to this thread. I'm having the same issue as Ceaver where after plugging it in, the pump goes for about a second then stops. Only after repeating it a couple times does it start filling as it should until the float goes up. Does this sound like a bad pump?
 

mecheng

New member
Me too

Me too

My pump has done this for a while now as well. I have also had to the pull the plug reset thing to get it to fill up the back chamber. I'd like to see about a pump replacement if that's possible also.

-Chris
 

rvitko

RC Sponsor
RC Sponsor
Be sure this is not the normal safety timer feature. They do turn off the pump after a preset time and will never run again until power cycled except to pulse the pump as an alarm, they are preset to 1 min 48 second for tanks up to 25, for 25-55 you need to extend the timer. The surest remedy is to send in the pump and controller. I have learned this since I posted to this thread. There is a software update that makes them less sensitive to the pump draw and generally replacing the pump is often a bandage that gets you a couple months before the problem is back, in fact the pump may be fine.
 

rvitko

RC Sponsor
RC Sponsor
Thank you, while they look the same the controller got a new circuit board in mid 2016 and new software in early 2017 and they are pretty robust now.
 
Top