What might have caused this?

[Nixid]

Discharge pipe from pump disconnected(?) with such force to bend the pvc pipe.

https://flic.kr/p/qMVhGt
https://flic.kr/p/qMVgrc
https://flic.kr/p/r5nQCv

 

[Citizen]

Discharge pipe from pump disconnected(?) with such force to bend the pvc pipe.

Can you repost pics, they are not popping up for me

 

[JasonLion]

My guess is that the flow was completely blocked somehow, and the water in the pump and connected pipe seriously overheated, weakening the PVC. With flow completely blocked, the pressure would be roughly 40 psi, and with the pipe weakened from the heat it could easily fail. That doesn't tell us where the blockage was however.

 

[pragmatic]

^Agreed! Heat definitely involved!

 

[ouachita]

Any chance freezing blocked the line and caused it to overheat like Jason said?

 

[Divin Dave]

Holy Cow!
Yeah, that got hot!

 

[chiefwej]

I had a similar thing and mine was caused by the failure of a check valve between the pump and filter. It was the flap type valve and the flap tore loose and got wedged so that it blocked the water flow. I don't see a check valve in your set up but, I agree something blocked the water flow causing the water to overheat. Block that flow long enough and the water will boil.

 

[Geelow]

Awful plumb job and pump running dry (heat)