Plumbing disconnected

[SumoSimo]

Hi all,

I had an emergency today. The pipe running from the pump to the filter dislodged itself while the pool pump was running (see attached photos). I was not at home since I had just moved out this past Saturday (7/16), so the home was vacant (tenant hasn’t moved in yet). Luckily, my neighbor noticed a lot of water flowing out of our backyard and turned off the pool pump for me. By this point, the pool lost 1/3 of its water.

Does anyone have any ideas why this could have happened? I’ve owned the home for a year, and this has never happened before.

 

[HermanTX]

Your multiport valve appears to be set to filter mode. And the inlet from the pump appears to have popped off. Could something have gotten blocked in the multiport valve or did the filter plug that caused it to overpressure? Are the threads in the multiport valve still in good shape? Really strange but something had to plug as you said it has been functioning for a year with no issues.

 

[generessler]

Either the threads are stripped, and water pressure just happened to choose this time to blow the joint apart, or it's vandalism.

The former could have been aided by a very dirty filter or obstruction in the valve causing a lot of pressure. Even so, the working pressure rating for a PVC 2" NPT thread is 280 psi. I don't think your pump can generate that even if completely blocked.

 

[Jimrahbe]

Sumo,

The only way it could have come apart is for the threads to have stripped. You can't turn that fitting, it just pulled out.

I suspect that your filter is way past being dirty..

Thanks,

Jim R.

 

[SumoSimo]

I was able to obtain a photo of the multiport valve on the filter. Just another data point that may help.

 

[JamesW]

Maybe the water got really hot and caused the fitting to shrink.

Undo the union and screw it back in to see if it is really loose.

Remove the Teflon tape from the threads and see if the threads are damaged.

 

[SumoSimo]

I'm also wondering about three other hypothetical scenarios that may have led to the incident.

1. Water level was too low and pump was sucking too much air.
2. Someone (mosquito guy) accidentally bumped into the pipe.
3. Multiport valve's position was adjusted (e.g. for backwashing) while the pump was on and was done in this manner over the years, gradually leading to the incident.

 

[almostakeeper]

I don't see any way that a pump has enough power to strip a large threaded fitting. Is it possible the installer accidentally cross threaded then corrected the screw on but with damaged threads.

 

[HermanTX]

I'm also wondering about three other hypothetical scenarios that may have led to the incident.

1. Water level was too low and pump was sucking too much air.
2. Someone (mosquito guy) accidentally bumped into the pipe.
3. Multiport valve's position was adjusted (e.g. for backwashing) while the pump was on and was done in this manner over the years, gradually leading to the incident.

1. it would still need to pressure up against something. Are the filter grids plugged?
2. Someone would need to fall onto it with weight to move it. That appears to be a fairly stiff connection from the pump outlet to the MP valve inlet.
3. It appears to be set in filter position (best I can see in picture). You can unscrew the top of the MP valve and confirm that it moves to all the various positions with no blockages. Agree, it is not correct to move the MP valve while pump it running - so if it did, it could have created a temporary block each time it was done and weakened thread over time.

I tend to think it was not threaded properly and over time it just failed. Or maybe a combination of someone leaning on it and some damage threads that weakened over time.
Suggest you undo the union. Take the half that screws into the MP valve and check the threads with another fitting with same threads (take it to Home Depot). Then inspect female threads in the MP valve, then take a new fitting with same threads and screw it in to see if it fits snug. (Purchase from HD)
Third - take the existing half union and screw into MP valve and compare its fit to the new fitting tried earlier.
If any doubt, I would purchase a new MP valve and new fittings to fit it. It will take more replumbing, but piece of mind is worth a lot in my book.

 

[JamesW]

Why is this one nut all corroded when the rest are fine?

The union looks like it was threaded all the way in as you can see in an older picture and you can see the color difference in the threads that indicates how deep the threads were.

In my opinion, the most likely explanation is that the threads got too hot and shrank.

Screw the part back in to see if it is loose.

 

[1poolman1]

Why is this one nut all corroded when the rest are fine?

The union looks like it was threaded all the way in as you can see in an older picture and you can see the color difference in the threads that indicates how deep the threads were.

In my opinion, the most likely explanation is that the threads got too hot and shrank.

Screw the part back in to see if it is loose.

View attachment 438354

View attachment 438355

Looks like someone used a standard steel nut on that bolt.