Burst ch pipe

[Alexstreet7]

Hi , got a service on the boiler was all fine , started noticing the upstairs rads half of them were not getting hot. Got the plumber round told me my pump is knackered in the boiler. Soon as the pump got changed 24 hours later a my flow or return pipe burst. Got it fixed happened again within 24 hrs rung bosh on advice told to get prv changed as was letting by ,Got the PRV replaced as it was letting air by started makimg funny noise got organised for bosch to revist as wasnt happy with funky noise . While waiting for engineer ,Burst pipe number 3 at this point few people scratching heads il post pics but I think there was huge kink in flow pipe. Do you think this could of been issue all along.

Don't feel likening can have boiler on while I'm not there anymore just incase it bursts again. Need some advice reassurance.

Cheers

 

[terryplumb]

Rodent damage possibly?
Any evidence of droppings ?

 

[Alexstreet7]

That was what the first plumber mentioned. No evidence what so ever no droppings no nothing.

 

[BlueLoo]

Plumbers and trade looking for other faults apart from the obvious.

1st fault mechanism was the boiler service.
2nd fault mechanism was the pump change.
3rd fault mechanism was the prv change.

Rodents are a long way down the list.

The 2nd last photo seems to show a longitudinal hoop stress failure of the pipe. This is a specific pressure generated failure.

Read the writing on the pipe. Pressure capacity is temperature dependent. 3barg @92c isn't a million miles away from a overpressured system (3bar max in the prv is usual) and a boiler temp not being shut down (kettling).
Both common enough things.
Both likely caused by idiot engineers.

The other photos suggest a hoop stress failure but also seem to be a bending rupture as well. Again, PEX expands like **** when hot so to much expansion and pipe wall on the limit and you get those failures. Also your pipe failures are on the area of pinch stress and your piping does seem offset in the other photos.

So I'm going with a system overpressure event caused by overheating leading to pipe rupture.

Sorting the boiler etc out is easy. You should change all the piping at least upto the point if last failure, at best, to the end of the runs.

I'd also be looking for a proper engineer to do a fault finding and see if the above it near the truth because you should lawyer up.

Assuming the install was done correctly and the last two engineers to look at were actual trades and not something else.

A ****ty place to be. You have my sympathy.


Ps read my sig, the above is a amateur observation. Not advise.

 

[Alexstreet7]

I appreciate all the knowledge and experience feom everyone. I just feel that these particualr engineers find what they want to find and fix what they want to fix with out fault finding the bigger picture. It's just frustratingly cliche coming into winter with no heating. I mean we are running electric heaters currently so it's okay.

In terms of replacing the pipe.work that had been spoken about changing to copper just the main spine of the run which is roughly 6metres so not to bad.


Cheers

 

[terryplumb]

What is the brand (manufacturer) of that pipe ?
You should send samples of the burst pipe to them for examination. How old is the pipework ?

 

[BlueLoo]

I appreciate all the knowledge and experience feom everyone. I just feel that these particualr engineers find what they want to find and fix what they want to fix with out fault finding the bigger picture. It's just frustratingly cliche coming into winter with no heating. I mean we are running electric heaters currently so it's okay.

In terms of replacing the pipe.work that had been spoken about changing to copper just the main spine of the run which is roughly 6metres so not to bad.


Cheers

The overstress will be throughout the entirety of the system subject to (probably) over temps and pressure so be sure to make sure you change everything upto, and somewhat past the last failure point in the direction of flow.
This means anything leading upto it all the way back to the boiler copper tails. (Or the start of the pex).
For piping under floorboards, you might want to look at getting a camera and checking for creases, ballooning etc.

You may be right about the main run only, i dunno, but i would be slow to rely on the plumber for advice.

It's simple logic. The failure mechanism worked its way from the start (boiler outlet?) To the weakest points.

 

[Alexstreet7]

I believe its PEX yeah I will have a good look through out as I have ripped half one room up. Another indication you could be correct with your extreme heat is that the grey lagging when pipe burst it basically welds the lagging to the pipe.

Then it's really hard to see where damage is.

So currently I'm running the boiler when I'm home turning off at night because the last burst was 3am which was odd because the boiler should of been sleeping technically untill it was calling at 6am.

I dunno pretty lost with this one but think I'm on right track

 

[BlueLoo]

Post pics of the pump, the prv and the boiler......

 

[Alexstreet7]

 

[Alexstreet7]

The temp is set at 67 degree but keeps fluctuating from 42 then goes right up to 72 keeps going up down up down.

 

[gas112]

Was there any thumping and banging coming from the boiler just before the pipe split ?

 

[Alexstreet7]

The temp is set at 67 degree but keeps fluctuating from 42 then goes right up to 72 keeps going up down up down.

 

[Alexstreet7]

Yes absolutly, first time it was almost idling at 3 bar with a banging and thudding and just as I was about to turn it off it.blew.

I avoided another burst in between 2nd and 3rd time as I was here it started to make the noise again so i shut it down before the inevitable happened.

 

[Harry Bloomfield]

The temp is set at 67 degree but keeps fluctuating from 42 then goes right up to 72 keeps going up down up down.

That would suggest to me, that there is a poor, or unstable flow through the boiler.