New central heating system

[ventzis]

Hi everyone,
I was just after a bit of advice on running pipes for a new central heating system, I had a search of the existing topics but didn't find an exact answer.

I'm going to be installing an entirely new central heating system, approx between 30-40 metres worth of pipework (split into 2 pipes), in a 2 bedroom ground floor flat.

I've been looking into whether to go for 15mm pipes or 22mm. So far, seems that the best way is to go for 22mm, but just wanted to see if that was the right choice?

 

[kevplumb]

22 main

15 branches

and it depends on how many rads

and the heating load

 

[ventzis]

Thanks for that, I forgot to mention the rads!

I will have 3 large rads, 3 small rads.

As for the heating loads - I was planning on having a Vaillant 831 boiler, which is overkill for the size of the flat, however I have seen some good offers on that model, and I think that having the larger model will mean that it will run less / not as hard anyway.

 

[kevplumb]

woa hang on what does your installer think

and it don't work the way you think

 

[ventzis]

Not sure yet, I'm only just beginning to try and work out how it will work, so installer hasn't been out yet, I just wanted to understand what I'd need

 

[kevplumb]

if your gonna do the calcs oversize your rads a bit (better to warm than to cold)

don't oversize the boiler (if your getting a combi it don't matter)

and bear in mind the gas supply might well need upgrading


one thing i would say is avoid 10mm plastic use 15

 

[ventzis]

Thanks for the advice.

I'm hoping the gas supply won't need upgrading as that was recently installed (in fact the old pipes that have been disconnected need removing as part of the job).