What is this plug and is it necessary

TX_Pool_Rookie

New member
Dec 22, 2020
3
Dallas, TX
Hi TFPers - I'm a new homeowner that inherited a large in ground heated pool/spa in the Dallas area. I'm trying to learn more about my new pool system. Currently, there is a leaking plug (see photos) on top of the pipe connecting to the heater. Based on my research it seems like it might be a vacuum relief valve. However, my system is not solar and it seems like those plugs are only used on such systems. Nothing else appears to be leaking and I'm wondering if the leak is impacting pump suction and possibly explaining why my Polaris vacuum seems slow and lazy (often barely moving). Happy to answer any clarifying questions if you can help me figure this one out.

Best!
IMG_1937.jpgIMG_1938.jpgIMG_1939.jpg
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
15,479
Evans, Georgia
I'm wondering if it wasn't an injection port someone put in after the build for chlorine or acid? Although that's an odd spot since you wouldn't be using the heater all the time so coming from the heater is weird.

My 2 cents.... and I'm NO pro! ;)

Maddie :flower:
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
20,793
Bedford, TX
TX,

I agree, an old temp probe for an automation system.. Show us more pics of the whole pad area..

When was the last time the filter was cleaned??? If you have suction side vacuum, a dirty filter can cause it to be "lazy"...

Thanks,

Jim R.
 

Bperry

Gold Supporter
Aug 20, 2020
133
Knoxville, TN
Pool Size
27000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
TX,

I agree, an old temp probe for an automation system.. Show us more pics of the whole pad area..

When was the last time the filter was cleaned??? If you have suction side vacuum, a dirty filter can cause it to be "lazy"...

Thanks,

Jim R.
Is the probe siliconed onto the outside of the pipe or did they drill a hole and insert it inside? Looks sketchy to me and if there is evidence of a leak, that would be the first place I looked.
 

TX_Pool_Rookie

New member
Dec 22, 2020
3
Dallas, TX
Thank you, all for the comments. Really helpful. The temp prob theory is enticing. @Bperry, I added the silicon a couple days ago to see if that stopped the leaking. It did not. I'll take some pics tomorrow morning of the entire pad for the thread to consider. @Jimrahbe, filters are pretty clean. I cleaned them about two weeks ago and checked a couple days ago and they looked good.
 

1poolman1

In The Industry
Jul 14, 2014
66
Sacramento
Don't know if you got your problem fixed yet. That is, indeed, a water-temperature sensor for the automation that is is/was in your system. Unfortunately some idiot installed it in the return line after the heater which is VERY wrong. If you look closely you will probably see that the pipe has partially "flattened" at the point the sensor is installed. Doesn't matter how much silicone you use or if you replace the "O" ring that is supposed to be there it will continue to leak. You should cut that piece of pipe out and replace it
 
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