New unvented system - ground floor losing pressure

[plastics77]

Hi there, wondering if anyone has any pointers, in the middle of a stressful refurbishment that was meant to finish a week ago! I am completely in the dark about boilers, but we agreed to the recommendation of a new pressurised unvented system that would feed direct off the mains (Vaillant ecotec, 300L cylinder for 5 bed house). This installation is part of a refurb of a late 1970's house, including installing 3 new bathrooms (tiling and sanitaryware), a new kitchen and new carpets and wood flooring.

So, most of the bathrooms have been re-tiled, and when they looked at the floors they noticed the pipes were 'metric' and needed replacing, so they replaced all the pipes in the bathrooms upstairs. Downstairs, the kitchen tiles have been laid and the ground floor cloakroom too. The plan was to start the wood flooring early next week, once the new boiler had been pressure tested - they have just done that and have said all works fine upstairs, but downstairs it keeps dropping pressure.

They are suggesting that there might be a leak in one of the pipes in the ground floor, although there is no evidence of any water leak and there were no issues with the older boiler and heating system before they installed this new unvented system. Is it the pressure of this new system that could have just blown one of the older pipes in the ground floor too? If they had said this could be a possibility we probably would have just stuck with the older boiler that was working fine for now!

Any ideas as to what I need to ask them before they investigate and decide sections of the ground floor now need digging up and pipes replacing? The project as expected has gone well over budget, and this was a nice Christmas present today
Thanks for any advice...gratefully received as very confused about the situation...

 

[ShaunCorbs]

what system did you have before ?

 

[centralheatking]

Hi there, wondering if anyone has any pointers, in the middle of a stressful refurbishment that was meant to finish a week ago! I am completely in the dark about boilers, but we agreed to the recommendation of a new pressurised unvented system that would feed direct off the mains (Vaillant ecotec, 300L cylinder for 5 bed house). This installation is part of a refurb of a late 1970's house, including installing 3 new bathrooms (tiling and sanitaryware), a new kitchen and new carpets and wood flooring.

So, most of the bathrooms have been re-tiled, and when they looked at the floors they noticed the pipes were 'metric' and needed replacing, so they replaced all the pipes in the bathrooms upstairs. Downstairs, the kitchen tiles have been laid and the ground floor cloakroom too. The plan was to start the wood flooring early next week, once the new boiler had been pressure tested - they have just done that and have said all works fine upstairs, but downstairs it keeps dropping pressure.

They are suggesting that there might be a leak in one of the pipes in the ground floor, although there is no evidence of any water leak and there were no issues with the older boiler and heating system before they installed this new unvented system. Is it the pressure of this new system that could have just blown one of the older pipes in the ground floor too? If they had said this could be a possibility we probably would have just stuck with the older boiler that was working fine for now!

Any ideas as to what I need to ask them before they investigate and decide sections of the ground floor now need digging up and pipes replacing? The project as expected has gone well over budget, and this was a nice Christmas present today
Thanks for any advice...gratefully received as very confused about the situation...

So when they put a 24 hour pressure test on the UFH what were the start and finish bar readings ? I would request a signed certificate timed and dated myself each visually checked by the main contractor So can you isolate the radiators upstairs from the naughty underfloor set up manifolds. Which UFH circuits drop..surely not all of them.
Just disconnect each in turn in pairs pump them up with a bit of mains and find your problem. After that its another problem I suppose but one circuit lala out of say 5 would not be the end of your floor. Or just destroy the contractor.
centralheatking

 

[Scott_D]

There was no mention of UFH?
What sort of test was carried out?

 

[centralheatking]

So when they put a 24 hour pressure test on the UFH what were the start and finish bar readings ? I would request a signed certificate timed and dated myself each visually checked by the main contractor So can you isolate the radiators upstairs from the naughty underfloor set up manifolds. Which UFH circuits drop..surely not all of them.
Just disconnect each in turn in pairs pump them up with a bit of mains and find your problem. After that its another problem I suppose but one circuit lala out of say 5 would not be the end of your floor. Or just destroy the contractor.
centralheatking

Oops I mistook under floor pipes for UFH but the same test principle applies. centralheatking

 

[plastics77]

Sorry, yes no underfloor heating anywhere!

They didn't mention any specific tests, just said we done a pressure test and its fine upstairs, where all the new pipes were put into the bathroom, but the pressure is dropping downstairs, where the floors have not been touched (apart from kitchen tiles and utility room, where the new boiler has been placed)

They said they will investigate further but it could be that some pipes in the ground floor might be leaking

The previous system was the previous owners, we haven't actually moved in yet, we were getting this all done before we moved in. I think it was a vented system, non-condensing boiler with tanks up in the loft - had recently been serviced and they said no problems with heating downstairs or upstairs, but the boiler was old and surveyor said had a 'knocking' sound so worth changing sooner rather than later...

 

[Scott_D]

A buyers survey probably would not have tested for leaks under the floor.
Pressurising old pipework can highlight leaks and weak spots.

 

[centralheatking]

We will have a think and try to give you an accurate course of action centralheatking

 

[plastics77]

Hi all, quick update and urgent advice please on this topic. So suddenly it all seemed ok and although not regularly or noticeably losing pressure over spring when we started using heating less, the pressure did drop once or twice and they asked us to keep filling it up back to 1.5bar.

More recently in last month or so, the pressure now drops from 1.2 bar to 0 overnight, around a 12hr period if the heating isn't on, and we wake up with no hot water or heating.

They came back and isolated upstairs from downstairs, kept it going for several days pressure stayed at 1.5 bar and no problem with heating upstairs (the works which they say involved some pipework change). As soon as they reconnected the downstairs, pressure dropped again so they say it's a slow leak in underfloor pipe somewhere and as they didnt do anything to those pipes its not their problem. However, as goodwill they stuck some sealant in saying 90% of times this works. They also re-bled all the radiators to make sure no air locks.

The pressure drop although initially very slow after this (1.5bar to hovering below 1.0bar, and everytime you put heating on it would creep itself up again to keep working), now is back to 0. I dont want to just keep filling up the system and I'm sure they will say it's a pipe leak issue now.

Before I contact insurers for track and access is there anything else I should ask these contractors to check that may still have been linked to their installation? Btw what does UFH stand for?

Many thanks