Low pressure

[tantontowers]

Have a 10,000 gallon in ground pool. Went to back wash after a storm last night but pressure was super low. Took out and cleaned DE filters, cleaned all baskets but pressure is still now only at 8 PSI after running pump for 30 minutes and also noticed no pop ups are popping up either. Also, put a small amount of DE in but it came straight back out from filter at bottom of pool.

Any ideas why pressure would still be so low and leaking DE?

 

[tantontowers]

Also, when I try to backwash now, I get zero pressure.

 

[jblizzle]

Did you add the DE on recirculate on accident? Clearly it should not be returning to the pool some something in the backwash valve or filter is not correct.

You must always add the correct amount of DE after backwash or cleaning or the grids will clog up.

It is normal for the pressure to be low when backwashing.

So, to be clear, the pressure is reading lower than normal and you are getting lower flow than normal?
That would point toward a flow restriction between the skimmer and the filter. Could be skimmer, pump basket, impeller ...

 

[tantontowers]

Yes, pressure is nominal, creeping slowly up to 8 PSI after a while. Checked skimmer, pump basket and impeller. All look okay. I checked the grids again for tears and they look fine. Did notice that there was no water at all in there though. Suggests pump not priming? How can that be fixed?

 

[jblizzle]

No water in where?
Do you see air in the pump? That would point to a suction side leak: http://www.troublefreepool.com/content/151-suction-side-air-leaks

 

[tantontowers]

No water in the housing for the DE filters, not sure the correct terminology for that. When I backwash now, it dribbles out a small amount of water and then nothing at all - pressure is zero for backwash and zero when pump is running normally. I see no leaks.

 

[jblizzle]

Is there air in the pump? Is the pump even turning?

 

[Richard320]

I'd look at the multiport valve or backwash valve. Sounds like the water is bypassing the filter completely. '

 

[tantontowers]

Ok I put some vaseline on the O ring for the pump basket lid and now I have pressure! Fluctuating between 16 and 18 PSI now but pop ups are not working now! I did notice a small hairline crack in the pump basket lid though so will replace that tomorrow and see if that does the trick.