Circ Pump getting Air locked! (Silent Flow 5000)

[EZcyclone]

So, long story short, I have a '03 TR Siberian.  LOVE this spa.  But it's been a pain in my ass lately.  The circ pump get's air locked OFTEN.  If both filters are in place it just wont stay pumping.  To me, it just seems like a weak pump, but the local HS dealer told me that if the pump spins, that means it plenty good.  And it does, the pump does spin, and pumps fine.  For a while.  One of the problems I think is that is a steady stream of bubbles coming into the pump from the supply line.  I have NO idea where they are coming from, I would guess they are not supposed to be there.  They are visible in the supply line entering the equipment compartment, so they are coming from somewhere beyond that. 

The pump pumps just fine and then you can just watch the flow (Ie all the bubbles) just slow down and stop moving.  If you turn off the circ pump, and wait 30 seconds, then turn it back on, it will fire up and run again for a while.  It could be 20 seconds, or hours.  You just never know.

I could really use some advice by folks that have been around more of these than I.  Right now my plan is to put a flow meter into the line and insert the programming that would test for flow, and if flow = false then "reboot" the circ pump.  But I would really like to figure out what's going on here.  I donno, I'm just very frustrated here. 

Any help would be great!  Thanks a lot.




It's taken a LOT of work to get it to where it is.  New heater, fixed a jet pump, built my own heater, had to build my own Arduino control system, built a mold to vacuum mold a new foot dome to fix a big hole melted in the bottom ETC.

[Isaac-1]

I had much the same problem with the circulation pump on my used Jetsetter when I bought it, replacing it with a new pump solved all the problems, flow was much stronger with the new pump (the new E5 style pump is much smaller than the older pumps, draws less power and moves more water).  As to the bubbles if you have an ozonator that is where they should be coming from.  Changing it out took about 5 minutes and was mostly trouble free (one of the spring clips on one of the hoses snapped and I had to improvise a conventional hose clamp in its place, thankfully I had one handy as I had also just changed out the ozonator due to age and one was provided with it)  I did not even drain the water, just worked fast and plugged pump / hose ends with a couple of wine bottle corks while I worked.

[EZcyclone]

It's funny that the local HS store told me that the pump was fine if it was running.  I have wondered all along if the thing could just be warn out.  The bubbles are not from the ozonator, they are coming into the pump with the tub water.  Long before the ozone injector.

[Kev B]

 When the pump is running, all the pipe or hose coming toward it is under suction and all the pipe after is under pressure. Turn off the breaker and look for any sign of dripping with it off. The pump you have may not be as strong as the new ones but that pump worked just fine originally and as the dealer said...if it truly is turning, and there are no leaks or blockages in it.

[clovett]

That is a ceramic pump.  If it gets bio sludge in it, or anything else, it will give you issues.  The same type of pump is used for PC water cooling.  They are super easy to take apart and clean, which may be all you need.

[kporter]

Are your filters clogged or old?

Porter