Return line clogged?

[Darkmanh]

Hello!
I have a diagram attached to this post that shows my pool pad. The return line that says "To Unknown" is what I'm asking about. When I turn the divert valves so that flow goes only to the "Unknow" line, the pressure goes up 15 psi at the filter gauge and there appears to be no flow View attachment pool.pdf Any suggestions on what to do to find out where this line goes? I was planing on capping it and be done with it.

 

[Texas Splash]

That's an outstanding illustration. You would normally get an "A+" for graphics, but since we know that one spa item on the right side should say spa return not drain, we'll have to deduct a point and give you an "A-". What I don't see is a line illustrating your return jets. Is that just assumed and splits-off from one of the 3-way valves? Since everything after the filter is on your pressure side, what about a pressure-side cleaning port? Do you have a small hole capped on the inside of your pool somewhere? That could be a pressures-side cleaner and something to investigate. If it was closed that could explain the pressure increase. Perhaps there used to be a water feature or auxillary use for that pressure line? Maybe I'm missing something else that others will reply to as well.

 

[Bama Rambler]

Since you have an infloor cleaner the extra branch is usually reserved for wall returns or some high flow water feature such as a slide, fountain or waterfall. Has your pool ever had a water feature that may have been hooked to that piping?

 

[Darkmanh]

That's an outstanding illustration. You would normally get an "A+" for graphics, but since we know that one spa item on the right side should say spa return not drain, we'll have to deduct a point and give you an "A-". What I don't see is a line illustrating your return jets. Is that just assumed and splits-off from one of the 3-way valves? Since everything after the filter is on your pressure side, what about a pressure-side cleaning port? Do you have a small hole capped on the inside of your pool somewhere? That could be a pressures-side cleaner and something to investigate. If it was closed that could explain the pressure increase. Perhaps there used to be a water feature or auxillary use for that pressure line? Maybe I'm missing something else that others will reply to as well.

Thank you for catching that! The jets are fed by the Spa return that I named “Spa Drain” in my illustration. It was a copy and paste issue. I always make those types of mistakes. :/ I have looked for any king of flow in the pool and haven’t seen any when I isolate that line with the diverting valves. I haven’t looked for a plug anywhere but I would think it’s easy to notice something like that. Aside from the spill overs I don’t have any other water features. I will do a more thorough examination of the pool walls. Could it be a line for chlorination exclusively. I was wondering if my pop up heads valve could be damaged by having a chlorine feeder before it so having a line exclusively for that would be a nice feature I guess?

 

[Darkmanh]

Thank you for the reply! I bought the house in February 2018 and I didn't hear from the seller anything about water features that used to be there. There are no obvious signs of a water feature that used to be there. It could be inside the pool itself so I will examine the walls of the pool more carefully to see if there's a plug somewhere. Thanks again!

 

[Bama Rambler]

If you don't have (or had) a water feature, I'd go looking for plugged wall returns either in the pool or the spa (more likely in the pool).

 

[Darkmanh]

Thank you for the responses! I looked at every wall and surface on the pool and I can't find any returns plugged at all. My pool has 14 pop up heads and the spa has 2 as well as 6 jets. So I researched a little and A&A has some features like QickSkim and Dekhlor which may be the reasons for the line but perhaps they didn't get installed. I'm not sure how to figure out if the line is clogged or if it's just capped on the other end. I was thinking on using an air compressor to try and blow out the line. Would that be a bad idea?

 

[Bama Rambler]

You could try an air compressor. Set the regulator to about 20 psi to start with and I wouldn't go above about 50 psi trying to blow it out.