Pool Leaking only when pump not running

[Kcdc42]

I have a 15K gallon gunite pool. I noticed that when I shut down the pump, the pool is definitely leaking. I ran the pump for 12 hours yesterday and did not notice the water level lower at all but it has already gone down by an inch or inch and a half since I shut down this morning (around 9 hours ago). Right now, I have shut down all equipment and checking if water level stops going below a certain level.

I did some research and found out that if leak is happening only with equipment off, it's on the suction side. But I am not sure what steps I should be taking to troubleshoot before I call in professionals (American Leak Detection, etc.).

To sum it up:

- Water level lowering when pool pump is turned off
- No visible water or pool of water near equipment or nearby ground.

Any suggestions or recommendations would be greatly appreciated.

 

[zea3]

What kind of filter do you have?

 

[Kcdc42]

What kind of filter do you have?

It's a Sand Filter. Here is a pic of the setup.

 

[zea3]

Where does the waste line end? Does it go into the ground or can you see the end of the pipe?

 

[Kcdc42]

I can see the end of the waste line pipe and it goes to the main street. I actually just checked and I see a small stream of water leaking from there onto the street. See video here:

https://drive.google.com/open?id=135FFupS7pabr_wK991ErA6Dj--KSEHHw

 

[PoolguyinCT]

That’s not a small stream.

 

[zea3]

Sounds like you need a new spider gasket in your multi port valve. It's a pretty simple diy repair.

i would either keep the pump running or cap the waste line until you can make the repair.

 

[Kcdc42]

Sounds like you need a new spider gasket in your multi port valve. It's a pretty simple diy repair.

i would either keep the pump running or cap the waste line until you can make the repair.

Ok, I am going to add more water to the pool and keep the pump running until I can fix this. Will have to look at some YouTube videos.

Btw, the Hayward pump is only a year old. Is the gasket supposed to go bad that quick?

 

[Catanzaro]

The Spider Gasket is in the Multi-Port Valve, and not the Hayward Pump.

 

[Kcdc42]

The Spider Gasket is in the Multi-Port Valve, and not the Hayward Pump.

Ok gotcha. I will take a shot at it this weekend. Thank you so much for your response and solution.

 

[Winnie-the-Pool]

The Multi-Port valve is the one you turn to backwash, rinse, filter etc. next to the filter tank.

I believe it's recommended to always turn it either clockwise or counterclockwise. Not doing so may cause premature failure of the spider gasket.

This is a good reason to have valves on all lines. If you had a valve on your waste line you could close it until you make the repair.

 

[JamesW]

The multiport looks odd. The handle doesn't look right.

Does the leak at the waste line happen when the pump is on or off?

 

[Kcdc42]

The multiport looks odd. The handle doesn't look right.

Does the leak at the waste line happen when the pump is on or off?

The leak at the waste line happens ONLY when the pump is turned off.

The handle is a little hard to turn around so I have to put some pressure. The pool/equipment came with the house when we bought it 5 years ago. I didn’t know the handle is supposed to be only turned in one direction. The handle does wiggle up/down when it’s at rest. I have included a link to short video on how the handle wiggles via the link below. Is that normal?

https://drive.google.com/open?id=1lcWBj04ZDJ2xiFWwgQWb4ECJqn-KEsQd

 

[JamesW]

Is the equipment lower than the pool?

 

[Kcdc42]

Is the equipment lower than the pool?

Yes they sit lower than the pool.

 

[JamesW]

Ok, that makes sense. When the pump is on, the force of the water pushes the diverter down and makes a seal.

With the pump off, the diverter does not make good contact with the gasket.

You need to disassemble the multiport and lube the diverter stem and replace the spider gasket if it's bad.

Normally, the spring in the multiport pushes the diverter down with enough force to make a good seal.

However, if the diverter stem is sticking and not moving smoothly, the spring can't push down hard enough to make the seal.

The diverter has 1 or 2 O-rings on the stem that goes through the lid and connects to the handle.

The loose handle and the fact that it's hard to turn means that the stem O-rings are gummed up and dry.

If you vacuum up sand, that can jam up the O-rings very quickly. Try to avoid vacuuming sand or at least use a skimmer sock to catch the sand in the skimmer basket and keep it out of the multiport.

The tab feeder can also damage the gasket and O-rings if the pump is off for long periods of time because the tabs continue to dissolve and the concentrated chlorine migrates through the system destroying everything it touches.

 

[zea3]

You have the side mount pac-fab multiport valve. You can see a parts view here: Pentair 2 Multiport Valve Parts

 

[JamesW]

That might be a 1.5" multiport.

What's the model number of the multiport?

 

[zea3]

Here's one for 1.5 pipes. Pentair PacFab Top Mount/ Side Mount 1-1/2 Multiport Valve - SM-10-3, SM10-2, TM12A, 261124, 261173, 261177

Thanks James, I didn't catch the 2" pipe on the first link.

 

[Kcdc42]

That might be a 1.5" multiport.

What's the model number of the multiport?

It says SM-20 on the top decal. On the side it says Praher SM2-PP3

picture for reference:
https://i.imgur.com/Lu65BUI_d.jpg?maxwidth=640&shape=thumb&fidelity=medium