Pressure side leak but pipes held pressure?

[penquinizer]

Hi!

I've had a leak in my pool for a few months now. Finally gave up and had a leak detection company come out to get it checked out. While they didn't run all the tests possible test that day, they did suggest rerunning my bucket tests to get a more accurate picture before they start other methods that would cost me more money. (diving, spa, etc)

After a few more bucket tests, I've confirmed it's leaking only with the pump on. From my understanding, this should mean it's a pressure-side leak. However, they did pressure test the return line when they came out and the pipes held pressure. Any thoughts on what it could potentially be? Would a bad gasket on the push-pull valve allowing a leak to the backwash be a potential cause here? Hard piped backwash though.

 

[JohnT]

Welcome to TFP!

A valve leak to waste is a very common failure, so I’d check that immediately.

 

[penquinizer]

Thanks for the quick response John! With the waste being hard pipped, is the only way to check ripping out the valve?

 

[ajw22]

Thanks for the quick response John! With the waste being hard pipped, is the only way to check ripping out the valve?

Does not take ripping out the valve to replace the O rings in the slide valve.

O rings wear and need periodic replacement. That is normal maintenance.

Slide Valves - Further Reading

www.troublefreepool.com

 

[penquinizer]

Gotcha! I was able to sneak a peak at the end of the waste line. It was difficult to see but looked very dry. tried pouring some water into it and there was a noticeable difference in the reflection of the bottom so I am currently assuming it's not leaking through the pushpull valve into the waste line.

 

[penquinizer]

I went ahead and pulled out the push pull valve. Everything looks okay. Also noticed a small hole drilled at the end of the waste line so water would have been dripping out if it was leaking there.

Back to square one.

 

[penquinizer]

Following up on this. Pump has been running in freeze mode for about 12 hrs now and noticed there's some moisture below it. I dont notice this when it isn't running in freeze protection mode / on a regular basis.

The seal around the lid seems dry and the pipes above also feel dry. Any thoughts?