Tunze 6105 Turbelle Stream issue

SDguy · Jul 16, 2020

I have a Tunze 6105 and 6255 connected to a 7096 multicontroller. The issue I am having is with the 6105. When I press feed mode on the multicontroller, both pumps stop as expected. However, when I either allow the time limit to run out, or I manually restart the multicontroller, the 6105 will not restart. Disconnecting it from the multicontroller still doesn't make it start. It isn't until I unplug and plug the power supply back into the junction module that the pump will restart. I have tried switching the pumps on the multicontroller, but still the same issue with the 6105, so I don't think the problem is with the multicontroller. Any suggestions? Since the pump is hard wired to the junction module, I assume it is not replaceable?

rvitko · Jul 17, 2020

Generally if a pump struggles to restart there is an impeller issue, likely the pump can only start at full power due to calcification, wear or a loose metal shaft, the titanium shaft should be rigidly fixed in the motor and not come out, the impeller spins on this shaft, if the 6105 was made before 2012, it may have an older design removable shaft, but this shaft will have a blue end cap on each end and the impeller should spin freely on the shaft and the shaft should fit snug in the seats on each end. I would remove the impeller and soak the motor and impeller in a mild acid (vinegar 50/50 or citric acid) for several hours until no calcium remains and be sure the metal shaft is fixed in the motor and drive units spin freely on the shaft.

SDguy · Jul 17, 2020

Thank you for the reply. The shaft was firmly seated in the pump. But during inspection with a flashlight, I did notice some "gunk" at the very bottom of the impeller housing. It's not mineral deposits, since this is a FO tank. So I took a recently purchased pipe cleaner and carefully cleaned the bottom of the impeller housing, being careful not to bend or otherwise disturb the metal shaft. Looks like that fixed the problem. I am surprised such a small amount of gunk would cause the issue, but your point about only starting at full power got me thinking. Thanks again

SDguy · Jul 19, 2020

rvitko said:
Generally if a pump struggles to restart there is an impeller issue, likely the pump can only start at full power due to calcification, wear or a loose metal shaft, the titanium shaft should be rigidly fixed in the motor and not come out, the impeller spins on this shaft, if the 6105 was made before 2012, it may have an older design removable shaft, but this shaft will have a blue end cap on each end and the impeller should spin freely on the shaft and the shaft should fit snug in the seats on each end. I would remove the impeller and soak the motor and impeller in a mild acid (vinegar 50/50 or citric acid) for several hours until no calcium remains and be sure the metal shaft is fixed in the motor and drive units spin freely on the shaft.

I think I spoke too soon. Yesterday the problem repeated. Then this morning, while in feed mode, the pump would randomly turn on and off, for brief periods. I checked all connections of the power supply and the multicontroller. All are securely plugged in. I think there is definitely something amiss with that junction module.

Also, regarding your previous comment about the pump only starting at full power. Wouldn't unplugging the pump from the multicontroller automatically result in the pump being at full power? Why do I need to unplug and plug back in the power supply as well to get it started?

Ideas welcome....

rvitko · Jul 20, 2020

If this is an older 6105 with the black junction box and no controller built in, unless you turned the potentiometer down on the box it would be at full power. These sorts of issues tend to occur when the pump is seizing because at low speed the power is too low to overcome the obstruction and it stops as a safety to prevent motor damage, at higher speed, it can power through. It would also be pssible their is an overlap, so the potentiometer was turned down and the controller speeds are low and the pump speed is too low to run.

SDguy · Jul 20, 2020

I don't see how any of that explains why it intermittently turns on during feed mode. It's also extremely clean. I don't see any reason for it to be seizing. Yes, it is the older model with the black junction box and no controller built in.