Low Flow except when set to waste

[leop1234]

I have been struggling with an issue with low flow. I have a 1.5HP hayward variable flow pump followed by a S210T sand filter followed by a hayward inline chlorinator. I am experiencing the following in each of the vari-flow positions:

Filtration - low flow and the pump chamber does not fill with water (1/2 full) but I can see a steady flow coming in
Recirculate - same as filtration with maybe slightly more flow but still pretty low
Waste- Full pressure with full prime and full pump chamber
Backwash - Full pressure with full prime and full pump chamber

I was initially thinking that the sand needed changing but since recirculate still has low flow I am thinking I have a clog somewhere in the return lines. I just bought the home/pool and it is very old with only 1 skimmer (and one working port) and 2 returns (24k gals). Any ideas?

 

[mas985]

What is the current filter pressure and what is the normal clean filter pressure?

Have you tried to backwash the filter?

Are all the plumbing valves open?

 

[leop1234]

Current filter pressure is around 23 PSI. I have backwashed and rinsed the filter and the only valve on the system is the waste line which goes to never never land.

Unfortunately I do not know what the clean pressure should be because I just moved into the home. The reason I initially did not think it was the filter was because the same lack of pressure occurs on the recirculate setting. Am I correct in assuming that will bypass the sand?

Thanks in advance for your help.

 

[mas985]

Yes recirculate bypasses the sand so it probably isn't a dirty filter.

Clogs in the return line are pretty rare because the filter prevents it most cases.

The other thing that could be a problem is a failed check valve. Do you have any check valves? If the flapper breaks off, it can sometimes clog the return line.

A picture of the pad equipment might help as well.

 

[edavis]

I don't know if this could be your issue or not but last night I took my sand filter apart which is intex brand and mine has a screen cover on the bottom of the valve assembly and it was plugged with debri and grass that had gotten past my strainer basket and through the system. I had low flow before but now I have a vortex circulating pool again.

 

[leop1234]

Thanks for the input. Unfortunately the flow issue occurs even when I bypass the filter. I will be taking some pictures or a video as soon as the rain stops!