Pump loses prime when under pressure.

[wags22]

My pump is losing prime when I set the filter valve to the filter setting. When I set it to recirculate it runs just fine, and will even start pumping again when switching back from filter. Switching to filter, after about a minute or two it visibly loses prime.

Any ideas what might be wrong?

Thanks for the help.
Jonathan

 

[ajw22]

look for suction side air leaks.

What is your filter pressure? When did you last clean the filter? You have DE in the filter?

Post pics of your equipment.

 

[wags22]

Any suggestions on how to flesh out suction side leaks?
Mine is a spa/pool setup. First picture is of the valves that control the spa/pool flow, currently set for pool only. Second picture is of the pump which I recently had taken apart, so I guess first step is to check that seal. Last picture is a cropped photo that shows the pump to filter to heater connections. I recently re-did the piping as I put in the multi-valve on the filter.

 

[mknauss]

The filter being plugged off due to algae can cause this. Can you post your latest test results? What does your pool water look like?

 

[ajw22]

It needs to be a pretty big air leak for the pump to lose prime. Usually suction air leaks just create bubbles. From what you describe things tay sealed in RECIRCULATE mode. When you go to filter the pump needs to work harder pressurizing the filter. Working harder is sucking harder and the pump begins to suck more air than water.

I asked about your filter - What is your filter pressure? When did you last clean the filter? You have DE in the filter?

 

[wags22]

I'm just getting things opened up for the season. I'd replaced the filter plunger valve with a multi-valve. I've got little to no d.e. in the filter and the water is dirty and was full of algae.

I've had this issue before with the grids getting clogged. Any suggestions on something to clean them and provide maintenance to keep them clean?

I haven't even begun testing the water because the pump hasn't been running.

And my apologies for the delayed response(s). I don't always get notifications (or see them come in) for responses and I've got other things on my plate that unfortunately come before the pool.
Thanks again,
Wags

 

[ajw22]

I'm just getting things opened up for the season. I'd replaced the filter plunger valve with a multi-valve. I've got little to no d.e. in the filter and the water is dirty and was full of algae.

I've had this issue before with the grids getting clogged. Any suggestions on something to clean them and provide maintenance to keep them clean?

You should never run a DE filter for more than 5 to 10 minutes without DE in it. Running it without DE will clog the grids and may ruin them. The only way to fix a DE filter after running without DE is to break it down and try and wash the grids. Backwashing will not clean the grids.

Now that you have a MPV you should run in RECIRCULATE while doing a SLAM Process. Once the algae is dead then you do a few cycles of filtering and backwashing to clean up the water.

 

[wags22]

Cleaned the filter and now it seems to not lose prime anymore. Should have known this as I've experienced it before. I'm experiencing other issues, but going to start a new thread.

Thanks again for the help.

 

[ajw22]

Keep your problems all under one thread. The history helps us.

 

[wags22]

As you wish ajw22:
I do have other threads on the forum, one of which was about running the pump dry. I took it apart, replaced seals, it seems to be running ok, but is quite noisy.
The issue I'm currently having is that my cleaner is barely moving. Water seems to be flowing normally over the spillway, so I'm unsure of whether it is an issue with the cleaner, the pump, or possibly the filter is clogged enough to reduce suction but not impede flow - the pool is very dirty.

I'm also getting a steady stream of air bubbles at the pool inlets. I suspect this is due to the cleaner hose not being tight. My plan for today is to pull the cleaner and manually vacuum the pool. I'm also going to do a flush and recharge on the filter.

Is there a way to share video or audio files to the site?

Thanks,
Jonathan

 

[ajw22]

As you wish ajw22:
I do have other threads on the forum, one of which was about running the pump dry. I took it apart, replaced seals, it seems to be running ok, but is quite noisy.

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[ajw22]

A dirty filter will affect the performance of a suction powered filter.

What was your filter pressure when you cleaned your filter and what is it now?

Load your video or audio files to Youtube or other hosting site and post a link to it here.

 

[wags22]

Thank you for the refresh on the rules ajw22. I was trying to keep posts under the section and of the forum.

I'm not sure what the filter pressure was after cleaning. Currently it is at 10 on a gauge that goes up to 60.

 

[ajw22]

You should note what your clean filter pressure is. It is important when trying to judge your flow and filter performance.

Your filter pressure is 10 at what pump RPM?

 

[wags22]

I tried to do a flush on the filter. The water coming out didn't look dirty. After setting it back to filtration, I looked over the pool and saw that the spa area (single inlet, outlet over spillway into pool) was now cloudy. The pool showed similar signs near the inlets. I snapped a couple of photos. First photo is what the spa water looked like after the flush. 2nd and 3rd photos show the pool steps and bottom of the pool in deep end, water is clear, but pool is dirty I'm wondering if one of the grids is leaking as some of the debris looks like D.E.

 

[ajw22]

Please post pics of your filter and valve on it.

You say flush but the standard terminology is backwash the filter. So I am not sure what you do in a flush. Please describe your flush process.

 

[wags22]

My apologies for the confusion. Yes, I'm doing a backwash. Initially I tried just moving the valve around while the pump was running. I just went out and put the system in service mode, stopped the pump, moved the handle, started the pump and let it run until it was clear. I did that 3 or 4 times until moving back to backwash setting the water started clear.
The confusing thing to me is that at this point the filter pressure gauge which was a solid 10 this morning, is now between 10 and 20 (see picture).

 

[ajw22]

First of all, you should never move the MPV handle with the pump running. Over time it will cause leaks in the spider gasket.

You should go to BACKWASH, let water flow for 2-3 minutes, then RINSE, flow for a minute or two, repeat 3 times. Turning pump off and on before each handle turn.

Then put handle in filter mode, turn on pump, note pressure, add DE, note pressure again. This is your clean filter pressure. Between 15-20 psi is what I would expect at full pump RPM.

 

[wags22]

Thank you for all the help a couple weeks ago. Issue was the pump basket was clogged from debris and D.E. recharge. Once I cleaned it out everything worked fine and the pool looks great.
New question: Usually I use Pool Perfect+Phosfree but I accidentally ordered just Phosfree. Realizing my mistake I then ordered Pool Perfect, but I'm not sure what ratio to use them in to get the same results of the pre-mixed product of which I was using a 1 1/2 caps a week for maintenance, 3 caps if I had heavy phosphates.
Again, thanks for the help.
Wags.

 

[mknauss]

None of those products are necessary or recommended.