Which pipe size?

[Clared]

I have a traditional gravity fed HW & pumped CH system and due to a refitting of my kitchen need to redirect a couple of the pipes.

On the gravity side the pipes are 28mm and I need to move them across the room slightly but most local DIT centres only stock 15mm and 22mm.

Do I have to use 28mm or will 22mm allow sufficient flow rate? Also if I need to use 28mm do you know where I can find this? I have only found one merchant so far but will only supply this in bulk and I only need a couple of metres!

 

[ChrisR]

You DO need 28mm at least - see a post hereabouts where a guy made small alterations and the flow stopped.
Any plumbers merchant will sell you 3m of 28mm.

 

[Bahco]

B&Q do 28 mm pipe
You do need to use 28 mm on gravity systems as they do not have a pump to assist circulation.

 

[Bahco]

Chris
You beat me to it again!

 

[oilman]

Just look at the posting time, why wasn't ChrisR out at work? Come to that why aren't I? There's a shortage of people to do plumbing type things.