Burst heating pipe (plastic)

[jonwm]

Live in a newish build (3 years old) and at 5pm tonight there was an almighty noise which sounded like a gravel lorry unloading on top of the house, lasted about 5 seconds but seemed longer.

Go upstairs to the airing cupboard and it seemed hotter than normal and all pressure had gone from the heating and radiators sounded like they were draining.

Few minutes later my daughter screams and water is coming into the lounge, great!

Emergency plumber has now cut my ceiling open and said he'd never seen a plastic pipe split like this before.

Fixed it with some copper but now I'm in bed paranoid that when the heating comes on in the morning it will be the same again as can't see how a pipe would just split like this.

Could there be a build up of heat / pressure or a blockage somewhere I need to sort?

Expansion vessel was hot to the touch and never noticed that before.

Can't get a heating engineer till next week

Any suggestions appreciated till I can get it looked at.

[NextSlidePlease]

Thats most deffinately a nick in the pipe rather than excess pressure, the fittings themselves are rated to like 10+ bar of pressure, the pipe probably several times that so doubt excess pressure or heat caused it, just a weak point which has finally gave way.

[jonwm]

Hi all

Revisiting this as since this I've had another pipe burst this time in multiple sections, I sent it this time to poly pipe who said it was heat. I have had my boiler checked by Worcester Bosch and they said its all good and couldn't get hot due to safety cut off etc.

Anyhow, fast forward to now and we contracted a new plumbing company as the last one (who installed it as a new build) have gone bust, we told him some of the issues and when checking the system he said the pump was installed the wrong way, all the lagging on the pipes in the airing cupboard which is quite far from the boiler have burnt onto the pipes indicated past or current high temps.

I'm booked in for a weeks time to have it turned round.
My question is, would this pump be pumping the system the wrong way round or would it just be running itself backwards?

I'm thinking if in reverse the boiler is checking the temps on the outbound flow (actually inbound) and just heating up with no control causing the water to be causing issue with the pipes?

Pump is a Wilos Yanos and system is about 6 years old now, pic isn't the best but pump arrow is pointing downwards and sits below this rail that has the heating and hot water valves coming of it, engineer said the arrow on this pump should face up to distribute properly through those automated vales.

Thoughts welcomed!

[Hobo]

Not sure where you live, but surely all new build homes come with a form of guarantee, ie NHBC or similar, which would cove this for the first 10 years and mean none of this would be at your expense.

[JoshSm]

jonwm said:

Hi all

I'm thinking if in reverse the boiler is checking the temps on the outbound flow (actually inbound) and just heating up with no control causing the water to be causing issue with the pipes?

Well, maybe, but you'd expect it to have been a bit obvious if everything was that hot? And usually there's a flow detection switch which are mostly directional? They do get stuck but this must have always been wrong.

Generally the system would only run until the thermostat cut it so overall it shouldn't have got hotter (it's still dumping the same energy), it'd still have hit a similar overtemp cutout so the boiler won't have got cooked, so at most it should just have been really inefficient as it won't have modulated to match demand.

Unless the thing was boiling - which it shouldn't have been able to manage - nothing should have been able to get to a point it was too hot and got damaged? Unless there multiple fkups with install and materials which there could well be.

[JoshSm]

PS. The pump can only run itself one way, no way it could reverse. They can purge either way up if the pump is designed for it but usually best to have the outlet at the top.

And an obvious easy way to tell if the system is pumping backwards is to check the pipes at the boiler, if the inlet one is hot after a quick bit of running that's a clue!

[No ideas for a name]

The pump can't run backwards, but of course it could be installed the wrong way around in the pipework and be causing the flow to be the opposite of that required.
If the insulation is physically burnt on to the pipe - unless it was done at soldering time - then it is physically getting too hot.
Has the PRV been checked? I assume since it has blown holes in the pipe the system is now off, and has zero pressure.
Does water come out of the expansion tank valve i.e. is if full of water with no air gap/expansion room?

I am a fan of non-pressurized hot water. Extremely rare, but the failure mode of pressurized systems isn't good.

[Sheepshanks]

Hobo said:

Not sure where you live, but surely all new build homes come with a form of guarantee, ie NHBC or similar, which would cove this for the first 10 years and mean none of this would be at your expense.

The developer should get the other properties on the estate checked too.

[jonwm]

Sheepshanks said:

Hobo said:

Not sure where you live, but surely all new build homes come with a form of guarantee, ie NHBC or similar, which would cove this for the first 10 years and mean none of this would be at your expense.

The developer should get the other properties on the estate checked too.

The first issue came 2.5 year in, this was then out of the 2 years warranty, I was told not there fault (didn't know at that point that the pump was the wrong way around).

I have checked other homes styles like mine, only 2 on the estate and they have no issues and pump pointing in the other direction.

10 year warranty only covers the buildings structural integrity not whats in it apparently.

[Sheepshanks]

jonwm said:

The first issue came 2.5 year in, this was then out of the 2 years warranty, I was told not there fault (didn't know at that point that the pump was the wrong way around).

I have checked other homes styles like mine, only 2 on the estate and they have no issues and pump pointing in the other direction.

10 year warranty only covers the buildings structural integrity not whats in it apparently.

I'd say the possibility of very hot water falling on people is a serious health and safety issue. Not quite the same thing but a kid died when an overheated water tank burst.

[OutInTheShed]

jonwm said:

The first issue came 2.5 year in, this was then out of the 2 years warranty, I was told not there fault (didn't know at that point that the pump was the wrong way around).

I have checked other homes styles like mine, only 2 on the estate and they have no issues and pump pointing in the other direction.

10 year warranty only covers the buildings structural integrity not whats in it apparently.

consumer rights act would cover wrongly built stuff forever?

Can you trace the plumbing to see which way the water is pumped through the boiler?

[jonwm]

OutInTheShed said:

jonwm said:

The first issue came 2.5 year in, this was then out of the 2 years warranty, I was told not there fault (didn't know at that point that the pump was the wrong way around).

I have checked other homes styles like mine, only 2 on the estate and they have no issues and pump pointing in the other direction.

10 year warranty only covers the buildings structural integrity not whats in it apparently.

consumer rights act would cover wrongly built stuff forever?

Can you trace the plumbing to see which way the water is pumped through the boiler?

Not really, Boiler is in the utility room downstairs and just has 2 pipes out the top, both painted white, its a heat only so no pipes underneath like i used to have on a combi.

[jonwm]

Sheepshanks said:

jonwm said:

The first issue came 2.5 year in, this was then out of the 2 years warranty, I was told not there fault (didn't know at that point that the pump was the wrong way around).

I have checked other homes styles like mine, only 2 on the estate and they have no issues and pump pointing in the other direction.

10 year warranty only covers the buildings structural integrity not whats in it apparently.

I'd say the possibility of very hot water falling on people is a serious health and safety issue. Not quite the same thing but a kid died when an overheated water tank burst.

This is what happened the 1st time, came thorough the ceiling red hot as it was the central heating pipe, luckily no one was in the room

[B'stard Child]

jonwm said:

Not really, Boiler is in the utility room downstairs and just has 2 pipes out the top, both painted white, its a heat only so no pipes underneath like i used to have on a combi.

Installation manual for the boiler should show you which pipe is flow and which is return

Sometimes they are also colour coded on the top of the boiler

[Hobo]

jonwm said:

Sheepshanks said:

Hobo said:

Not sure where you live, but surely all new build homes come with a form of guarantee, ie NHBC or similar, which would cove this for the first 10 years and mean none of this would be at your expense.

The developer should get the other properties on the estate checked too.

The first issue came 2.5 year in, this was then out of the 2 years warranty, I was told not there fault (didn't know at that point that the pump was the wrong way around).

I have checked other homes styles like mine, only 2 on the estate and they have no issues and pump pointing in the other direction.

10 year warranty only covers the buildings structural integrity not whats in it apparently.

Whilst it is correct that years 3 to 10 only cover structural matters in reality, latent defects would still results in liability being with the builder, ie something that was fundamentally incorrect at time of build which has only come to light outside of the 2 year period of cover. Thier PI insurance would cover this, regardless of the warranty.

[jonwm]

Hobo said:

jonwm said:

Sheepshanks said:

Hobo said:

Not sure where you live, but surely all new build homes come with a form of guarantee, ie NHBC or similar, which would cove this for the first 10 years and mean none of this would be at your expense.

The developer should get the other properties on the estate checked too.

The first issue came 2.5 year in, this was then out of the 2 years warranty, I was told not there fault (didn't know at that point that the pump was the wrong way around).

I have checked other homes styles like mine, only 2 on the estate and they have no issues and pump pointing in the other direction.

10 year warranty only covers the buildings structural integrity not whats in it apparently.

Whilst it is correct that years 3 to 10 only cover structural matters in reality, latent defects would still results in liability being with the builder, ie something that was fundamentally incorrect at time of build which has only come to light outside of the 2 year period of cover. Thier PI insurance would cover this, regardless of the warranty.

Thankyou, appreciate that info. I will certainly calm them when back from holiday, we fly out tomorrow for a week.

Much appreciated

[jonwm]

B'stard Child said:

jonwm said:

Not really, Boiler is in the utility room downstairs and just has 2 pipes out the top, both painted white, its a heat only so no pipes underneath like i used to have on a combi.

Installation manual for the boiler should show you which pipe is flow and which is return

Sometimes they are also colour coded on the top of the boiler

Downloaded the manual, can confirm after climbing up onto the work surface that inlet pipe is red hot, outward bound is noticeably cooler so it's going the wrong way round the system.

[B'stard Child]

jonwm said:

B'stard Child said:

jonwm said:

Not really, Boiler is in the utility room downstairs and just has 2 pipes out the top, both painted white, its a heat only so no pipes underneath like i used to have on a combi.

Installation manual for the boiler should show you which pipe is flow and which is return

Sometimes they are also colour coded on the top of the boiler

Downloaded the manual, can confirm after climbing up onto the work surface that inlet pipe is red hot, outward bound is noticeably cooler so it's going the wrong way round the system.

That’s probably sub optimal for boiler efficiency too

[biggiles]

A couple of wifi thermometers are £20 each, and would give you some real numbers to prove and demonstrate the problem. And reassurance afterwards that it's fixed. It sounds pretty rare for this to happen.