Tunze 6105 Impeller Frozen

[sluicebox]

I have two Tunze 6105's purchased in July 2014. I am using an Apex to control them. I have noted the Tunze instructions stating that other manufacturer's controllers are not to be used with this pump. However, it seems that everyone with an Apex uses it to control them. Also, the Apex instructions say that the pump should not be operated at less than 30% which I have complied with for all the programming.

Anyway, I have had both pumps to lock up about the same time in two different instances. In November, both were locked up and I cleaned them both with a vinegar bath and they began to operate again. I noticed that the impellers were very tight. But, after the vinegar bath, it seemed to be better. Now, three weeks later, they are both locked up again. It seems that the magnets are frozen to the shafts in both pumps. It is really strange that both seem to fail at the same time or at least within one or two days of each other. I'm currently cleaning again in vinegar but I am doubtful that it will work this time.

Has anyone had similar problems with this pump? If it not for the Apex, what else could be causing the problem? I have not contacted Tunze support yet but will on Monday morning.

 

[mcarroll]

Just to offer an additional course of logic to consider, it sounds like it could be precipitation from dosing. (Been there.) Are you adding any calcium/alkalinity products? What and how?

 

[sluicebox]

Yeah, could be. I am dosing BRS 2-part CA and Alk. Have you had similar experience? If so, did you solve the problem. I can't clean these every week.

 

[sluicebox]

Yeah, could be. I am dosing BRS 2-part CA and Alk. Have you had similar experience? If so, did you solve the problem. I can't clean these every week.

Using a dosing pump to add the 2-part.

 

[mcarroll]

Yeah, could be. I am dosing BRS 2-part CA and Alk. Have you had similar experience? If so, did you solve the problem. I can't clean these every week.

Using a dosing pump to add the 2-part.

I have. You might read back through my threads.

You may have to experiment a bit or consider different options depending on your particular installation, but you can do some or all of the following:

*dilute the 2-part (I usually cut it by 50% with RODI)
*make smaller, more frequent doses
*make smaller drips
*make sure NONE of the drips drift into/get sucked into the pumps
*consider switching to baking soda for alkalinity from wasahing soda...its barely-noticeable lower pH is less likely to contribute to local precipitation(...and it's cheaper and more Green.).

I also make sure to dose when the skimmer is off (mine only runs 6 hours a day) into my sump where I have lots of open space and a ton of circulation. The drips would have to navigate the whole sump, in turbulence, before reaching a pump inlet.

$0.02.

-Matt

 

[rvitko]

If the KH and alkalinity run high, the pump may need disassembly and cleaning as often as every 3 months, I would term high as anything about about 400ppm Ca and 10-12 dKH. When you clean them, remove the propeller assembly before soaking the impeller and pump. I don't think the controller is part of the issue, it is just a matter of the interaction of calcium, KH, pH and the heat and vaccuum generated in the pump causing precipitation.