Filter air relief line routed back into plumbing

[AerospaceCowboy]

I noticed the air relief valve on top my starite system 3 cartridge filter is leaking. Looking into replacing and discovered someone previously installed a line from the air relief back to the return side (bypassing the heater). Is this normal practice? Do I not need to open this line to remove air from the system after servicing (as the manual states)? Perhaps this was installed to remove the need to do so.

It's hard to tell from the photo but the black line running from the top of the filter on the left is routed to near the automation valve near the heater on the right.

 

[DavidArmenB]

I suspect this was done so when you relieve the air and water comes out, the water goes back into the plumbing as opposed to spraying out the side of the filter. However, pressure differences may cause the air to not leave the filter so I’m not sure what the point of that setup is.

 

[AerospaceCowboy]

To clarify, the valve is always open. So when there is air in the filter it will purge it through the plumbing back into the pool. However, when there is no air in the system water is constantly coming from the top of the filter back to the pool. I'm not sure if that's common practice or a good approach. I'm not too knowledgeable on how the filter works, but I assume this water is bypassing some filtration when it is running since it isn't going out through the filter exit. Do others have this same setup with their air relief valve?

 

[DavidArmenB]

Definitely not common practice.

Exactly, Some water is constantly bypassing the filter. Is the other end of the hose connected to the pipe after the filter? If so, you are constantly getting unfiltered water back into the pool.

 

[AerospaceCowboy]

That's correct. The line is routed from the top of the filter to the output of the heater. Essentially, bypassing the filter exit and the heater, and entering the heater exit. Sounds like I should remove this line and patch up the hole where it enters.

 

[DavidArmenB]

At the very least, close the air relief valve on the top of the filter. But yes, eventually you’ll want to remove that line so when you relieve air from the filter and then water starts to come out, it will not go into the pool before you close the air relief valve and you will have visual indication when all the air leaves the filter.

 

[1poolman1]

I noticed the air relief valve on top my starite system 3 cartridge filter is leaking. Looking into replacing and discovered someone previously installed a line from the air relief back to the return side (bypassing the heater). Is this normal practice? Do I not need to open this line to remove air from the system after servicing (as the manual states)? Perhaps this was installed to remove the need to do so.

It's hard to tell from the photo but the black line running from the top of the filter on the left is routed to near the automation valve near the heater on the right.

Close the valve, remove the tube, you're good. Block it off wherever it is attached to the plumbing.
Any air in the filter will be released by the internal air-relief screen and tube. You only need to open an air-relief before servicing the system, not after. You want to be sure there is no residual pressure to cause harm.
Virtually impossible with a System 3 filter and all those clamps holding the tank together. Pressure would be released long before enough clamps were removed to allow the lid to hurt someone. That's one of the reasons it was designed that way.