Installed Unvented cylinder will cause water pressure high?

[Jurgenjay]

Dear all,

I recently got a gas engineer installed a new boiler and an unvented cylinder & expansion vessel in my house, replaced the old boiler, vented cylinder and water tanks in loft.

Just after a month of installation, last week, the house lost hot water, it was because the cylinder leaked water heavily, we found it leaked to downstairs utility room via underground hot water pipes which could see cracks or fractures and leaked water.

Today, the water burst out from bathroom sink tap which was broken/separated from the sink, flooded all room. We can see the tap was broken into two parts,

So we suspect it is water pressure made the underground hot water pipe cracking and sink tap broken into two parts?

I heard the installation of unvented cylinder & expansion vessel will increase the water pressure on the pipes, do you think what happened to my house is the cause of the installation of unvented cylinder & expansion vessel?

Notes: the house is 40 years old, the pipes underground are old. The house previous owner was an over 90 year old single lady who sat to use shower, the house could not stand up to use shower as the water pressure was very low.

Since we moved in, we got unvented cylinder & expansion vessel installed to have good shower pressure, so is this the reason that water pressure increased and damaged the water pipe and sink tap (sink tap might be quality issue, but shouldn't be broken by water pressure?)

If it is water pressure cause the pipe broken and water leak, what should we do? Change the pipes??

Please help!

Many thanks!

 

[ShaunCorbs]

Yes it not helped but the pipe would of gone eventually

As for the tap I would put it down to a cheap tap / bad manufacturing

 

[Jurgenjay]

Yes it not helped but the pipe would of gone eventually

As for the tap I would put it down to a cheap tap / bad manufacturing

Hi, thank you for your prompt reply!
Did you mean unvented cylinder & expansion vessel installed is the reason made the water pressure increased and therefore crack the pipe?
I kind of agree the tap broken may be down to cheap/bad manufacturing, btw, the tap cost me £65 which is not cheap one although not expensive at all.

 

[Scott_D]

Was the pipe in the concrete protected in any way?

 

[Jurgenjay]

Was the pipe in the concrete protected in any way?

No, no protection of the pipes.
The house is 40 year old, that time no protection for underground pipes?

 

[Scott_D]

The unvented cylinder will have increased hot water pressure but you cant blame the new install for poor existing pipes and fittings

 

[Jurgenjay]

The unvented cylinder will have increased hot water pressure but you cant blame the new install for poor existing pipes and fittings

So the unvented cylinder & expansion vessel does increase the hot water pressure, which is the cause the pipe crack and leaking water. Thank you!
If in this case, to avoid more water leak problem, what do I need to do? To replace the pipes?---Is this the only way?
Thanks!

 

[Scott_D]

So the unvented cylinder & expansion vessel does increase the hot water pressure, which is the cause the pipe crack and leaking water. Thank you!
If in this case, to avoid more water leak problem, what do I need to do? To replace the pipes?---Is this the only way?
Thanks!

Yes but copper pipes shouldn't be in direct contact with concrete so it was going to happen eventually.
Best to get the sections repiped

 

[Jurgenjay]

Yes but copper pipes shouldn't be in direct contact with concrete so it was going to happen eventually.
Best to get the sections repiped

"get the sections repiped"----you mean those repipe are underground & or upstairs that direct contact with concrete?

 

[Ric2013]

It would be interesting to know how high the pressure became and what the arrangements for expansion and over-pressure situations are.

Taps and pipes are usually tested for maximum 10 bar pressure so it's quite odd that they should fail even if they were old as the pressure might have been kept quite reasonably well below this. I would like reassurance that the correct safety arrangements for limiting the maximum pressure are in place...

 

[Jurgenjay]

It would be interesting to know how high the pressure became and what the arrangements for expansion and over-pressure situations are.

Taps and pipes are usually tested for maximum 10 bar pressure so it's quite odd that they should fail even if they were old as the pressure might have been kept quite reasonably well below this. I would like reassurance that the correct safety arrangements for limiting the maximum pressure are in place...

Hi how to know the pressure now?---this needs the installer to test?
the arrangements for expansion and over-pressure situation---this needs the installer to tell?

The tap actually brand new...

reassurance that the correct safety arrangements for limiting the maximum pressure are in place...====this again needs my installer of boiler to tell?
Otherwise, how to find out if there's any safety arrangements for limiting the maximum pressure?

Thanks!

 

[king of pipes]

Believe it or not it's quite common to have issues with existing pipework on upgraded old systems none of us know what condition the pipework is in and how worn it is ? These problems need to be addressed when they occur and unfortunately sometimes it can be a total re pipe or at least a replacement of faulty sections, your installer should of at least made you aware of the possible problems I always put it in writing to cover eventualities should they happen . Kop

 

[Ric2013]

Hi how to know the pressure now?---this needs the installer to test?
the arrangements for expansion and over-pressure situation---this needs the installer to tell?

The tap actually brand new...

reassurance that the correct safety arrangements for limiting the maximum pressure are in place...====this again needs my installer of boiler to tell?
Otherwise, how to find out if there's any safety arrangements for limiting the maximum pressure?

Thanks!

I wouldn't bother actually measuring the pressure but if you can post some pictures of the new cylinder and how it is plumbed in, that will give us some idea. Realistically, it's probably fine and it's just one of those things.

 

[Jurgenjay]

I wouldn't bother actually measuring the pressure but if you can post some pictures of the new cylinder and how it is plumbed in, that will give us some idea. Realistically, it's probably fine and it's just one of those things.

Please see the photos as requested.
Thank you!

 

[Jurgenjay]

Believe it or not it's quite common to have issues with existing pipework on upgraded old systems none of us know what condition the pipework is in and how worn it is ? These problems need to be addressed when they occur and unfortunately sometimes it can be a total re pipe or at least a replacement of faulty sections, your installer should of at least made you aware of the possible problems I always put it in writing to cover eventualities should they happen . Kop

Sadly, my installer did not tell me this, and told me unvented cylinder wouldn't give more pressure.....until the leaks happened twice and then I did research and found it will increase pressure indeed!

 

[Ric2013]

I don't have an unvented certificate so I'm no authority on this, but I can't see any obvious problems with the installation.

 

[Jurgenjay]

I don't have an unvented certificate so I'm no authority on this, but I can't see any obvious problems with the installation.

Thanks! No problem!