Air in strainer basket.

[gonzodog]

I have a leak somewhere in my system, just struggling to find it. I have checked, rechecked, replaced, and lubed the O Ring at the strainer basket on the pump. I still get air in the strainer basket. When I put the system into backflow, the basket fills up and no air bubbles, but when in normal operations, it is getting lots of air, especially when running on low speed.

I've checked the drain plugs. I don't have a union joint coming into the pump. I saw one suggestion to replace the motor shaft seal. That seems like my next logical option, I guess.

I just can't figure out why I get air in the strainer when running normally, but not when in backflow. Any way air could be getting into the system after the pump that would be causing the air in the lines?

I cleaned out the DE filter and replaced the O Rings, just to be sure as well.

Motor shaft seal is my next step, unless someone else has another suggestion.

Thanks,

Gonzo

 

[Texas Splash]

Gonzo, when you say back-flow, I'm guessing that's when you are backwashing correct? You've addressed a few of the most common suction-side concerns for air. Is it safe to assume the pool's water level is good, and the skimmer weir door is operating properly? No other items before the pump like a 3-way valve, check valve, etc? If not, then while rare, it may also be a suction line issue underground. If that's the case, you may be left between trying the pump seal and/or perhaps conducting a pressure test of the suction line. That's what comes to mind for me, others may have another thought or two.

 

[Jimrahbe]

Gonzo,

Do you have a two speed pump?

Are we talking about a bubble that floats above the pump strainer basket or so much air the pump can't prime?

Does it have air in the basket when in low speed and high speed or just low speed?

I would interested in knowing if a new shaft seal fixes the problem, if you go down that route.

I know that as my filter get dirty, the bubbles in my pump get larger.. What is your filter pressure when the filter is clean with fresh DE?

Let's see what our other members have to say,

Jim R.

 

[gonzodog]

Correct, backwashing, not backflow. Water level is good and weir is working correctly.

There is a 3 way valve prior to the pump (could be an issue). Ugh.

I do have a 2 speed pump. Issue is a problem with both speeds, but really bad with low speed. Haven't had this issue until recently, and have had dual speed pump for a couple years.

Filter pressure with clean DE is now 10, so very low.

Could be the 3 way valve or motor seal. What is confusing me is that the pump works normally when in backwashing mode. Makes me think the issue is filter side, not pump side. But, why would filter side cause the strainer basket to get air? I've ordered a new O ring and new lid, just to be safe. I think I'll replace the motor seal out of precaution.

If it is the 3 way valve, that will suck, since it is all PVC and cement and not easily replaced.