Compression joint integrity with increased pressure

[Psithyrus]

I have a very old Ideal Standard boiler with a reserve tank in the roof. About six years ago a plumber fitted a compression joint underneath a newly laid wooden floor whilst it was being laid, and this has been satisfactory.

I am now thinking of replacing the boiler with a new system, perhaps a 'Vaillant Ecotec 628 HE System Boiler & un-vented cylinder' but am worried that with the pressurised system the compression joint might spring a leak as I am on a high floor in a multi-story block.

Am I needlessly worrying do you think? Is the risk of a new leak due to the increased pressure significant?

Any advice would be gratefully received.

 

[Riley]

Any reason why he insisted on using a compression where it can't be accessed?

 

[Centralheatking]

Moving from an open vented system to a pressurised system can cause small leaks on all sorts of joints, rad valves etc. Get your fitter to put a pressure test on if it worries you. Its not usual
and go for it anyway - a controlled watched for leak is way better than not being prepared.
I trust you are changing the radiators as some 'very old' ones will not take 1.5 bar CHK

 

[newcastle phill]

Regarding the compression joint.....well your asking so you know the answer.

Be prepared to have your unvented cylinder serviced annually. Its a requirement

 

[Psithyrus]

Thanks very much for the advice.

Actually I wonder if I really need to install an unvented system or can I just install a conventional 'Vaillant Ecotec 428 HE' boiler? Then I wouldn't have to worry about pressure leaks.
Is that a reasonable choice do you think, I mean would there be any significant drawbacks?

Again any advice would be most gratefully received. Paul

 

[gmphbrighton]

The 428, only draw backs of not converting to unvented is you wont have mains pressure hot water. Depending on quality of your supplies in the block you may not actually see any benefits from unvented.

What size is the property? You say you're in a multiblock so i take it it's a flat 1 2 3 bed? are you sure you need a 28kw?

I think the best thing to do would be to get a suitably qualified plumber in to advise you on the best system for your sitaution.