Burst plastic piping.

[Martin Dunne]

Hi all,

I have a recurring problem with my central heating system, the pipework from my boiler to the hot water tank keeps on bursting, it has occurred 3 times now. The pipe is 28mm Hep2o and it is physically splitting the pipe, not blowing off at the fittings.

The house is 9 years old and this is the 3rd time it has happened, always on the same piece of pipework, should there be some pressure relief to prevent the pipe from bursting as when it bursts it pretty much explodes.

Does anyone have an idea as to what the issue could be? Is it a defective peice of pipe or is there a fundamental problem with the system?

 

[Ric2013]

How close to the boiler is the pipe? In terms of metres or feet of pipe run.

 

[Martin Dunne]

The closest the pipe has burst is approx 4 metres from the boiler, the furthest is about 7 metres.

 

[Ric2013]

That isn't too close to the boiler.

If this is a sealed system there should be a pressure release dump set at 3 Bar, often incorporated in the boiler. Hep should be good for 6 Bar even at 90°C...

 

[Martin Dunne]

Yes it is a sealed system. Boiler is an ideal isans.

 

[Martin Dunne]

 

[oz-plumber]

If I were you, I would send the pics to the manufacturer of the pipe.

I would go as far as requesting someone from the manufacturers to come and inspect the pipe.

If this has happened on the same piece of pipe on 3 separate occasions, they will be interested in testing the pipe.

 

[Ric2013]

The same batch of pipe, or the same section within your installation?

I wonder if the PRV is seized?

 

[ShaunCorbs]

The same batch of pipe, or the same section within your installation?

I wonder if the PRV is seized?

Wouldn't be in the same spot tho every time

 

[Ric2013]

Yeah, presumably the OP has bought a length and keeps using this batch to repair the damaged section?

 

[Scott_D]

Any rodent problems?

 

[rpm]

Any rodent problems?

No signs of teeth marks on that section of pipe.

 

[Martin Dunne]

The damaged pipe is the original pipework installed when the house was built. I have patched it twice now but obviously something is amiss.

 

[ShaunCorbs]

If you still have the split piece I would send it to the manufacturer and ask them to analyse it to see if they can pin point it

 

[Harvest Fields]

Definitely get the manufacturer involved. You never know they may admit fault!!

 

[Scott_D]

Any pictures of the boiler? Could the pressure relief have been capped off or isolated?

 

[Chuck]

It could be a batch of faulty pipe, but I doubt it. Given the consistent way it's failing, it is more likely to be an incorrectly designed/installed system. The expansion vessel might, for example, be on the wrong side of a zone valve so it's isolated when you are just heating the HW tank. Numerous other possibilities. We need to see photos, please. Lots of photos.

 

[AWheating]

Remove sction of pipe and pressurise to 20bar and see what happens. Go higher see what fails

 

[AWheating]

Wet test tho, not air

 

[Martin Dunne]

I'll try and get some pictures added, working 12 hour shifts so haven't had time to do a great deal.

Thanks for all the replys

 

[oz-plumber]

Definitely get the manufacturer involved. You never know they may admit fault!!

The only fault they will admit to is an installation fault!!!

Excuses:
- Never ever seen that with our product.
- Our quality control systems wouldn't allow that to happen.
- It must be due to damage in transit - we can't be held accountable.
- Something has caused external damage to the pipe causing the pipe to rupture.

 

[Martin Dunne]

Here are some photos of the system

 

[Martin Dunne]

And some more

 

[Martin Dunne]

Does it matter which side of the pump the PRV goes?

 

[ShaunCorbs]

Does it matter which side of the pump the PRV goes?

For what ? You've already got one on the expansion vessel kit