Fitted a new boiler with 15mm pipe, but unsure if the old 10mm pipe to radiators is fine?

ahsih

Hi guys,

I have a quote from the gas engineer to recommend me upgrading my pipe to 15mm, currently I am still in budget , so I am not sure if this is fine?


Thanks.

grumbler

What do you mean by "fitted a boiler with a 15mm pipe"? What pipe it was with the old boiler?

If radiators are connected individually, like above, the main pipes are usually bigger in diameter than the 'branch' pipes to radiators.

Bendy_House

Yes, need more info.

If your existing rads are supplied in 10mm pipe - like many newer builds are - and this works fine, then the new boiler should also work just fine.

I presume, tho', that the Flow and Return pipes from the actual boiler will be larger than 10mm, in fact almost certainly 22mm? In which case it's likely these go to a 'manifold' where each rad then gets its individual supply via 10mm pipes. In which case, now't wrong with that.

As part of the new boiler installation, the existing system should be given a thorough clean, and this will be a bit more important since 10mm will be easier to block with sludge than 15mm pipes.

On a different - tho' possibly connected - issue, I don't see how it's a 'safety' issue to have 10mm pipes entering the rads. Do these pipes come up to the rads from the floor, or from the wall? If the former, then perhaps they are showing signs of having been bashed by a Hoover or similar?

If it's a matter of aesthetics - these 10mm pipes just look bendy and ropy - then the simplest solution is to slip 15mm pipe covers over them to hide them.

Photo of a typical rad with the 10mm pipes, please? And a photo of the pipes that exit from under the boiler.

EssexExile

As above, we have 22mm from the boiler to manifolds then microbore to each rad. I don't understand the safety point, we've been here 20 years and we've had a couple of blockages but other than that, no problems. I think the system has been in since the 70s.

fenwick458

I have just bought a buy to let with CH pipes after the manifold in 8mm upstairs & 10mm downstairs. plenty of people who have looked round the house (tradesmen) have commented on how bad these are "supposed to be"....
these pipes have been in for 30 years, and they still work.
also when thinking about this I was reminded or my first house, had exactly the same setup and was a bit older, still worked fine...and still works fine now and it was installed in the 70's.
if it aint broke, don't fix it. needless to say, I'm much more a fan of microbore copper from the 70's compared to 15mm push fit rubbish you can buy today from whichever discount trade outlet.

Bendy_House

There is nothing inherently wrong with microbore, and they make a lot of installation sense. However, they do rely on the system being kept in good order, with a nice dose of inhibitor so that no internal rust can form.