10mm or 15mm pipe for rads+towel rails

[Chablais]

Hi 

just trying to decide if I should use 10mm Hep20 or 15mm Hep20 pipe to feed three radiators and four towel rails via a manifold. 10mm is much easier to run and turn etc. but when you look at the inside dia. compared to the 15mm especially with the insert in,  the difference looks huge. Will it create too much resistance or be prone to noise and clogging. The runs will be circa 5-8 metres between manifold and rads. Would it be possible to mix the pipe dia on the same manifold. Have used 10mm pipe to the basins and 15mm to the kitchen sink on the potable runs.

Finding the plumbing a little more confusing than anticipated!

[Conor]

There was a post a couple days ago about this very topic, have a search and you should find it.

 

Spoiler alert: 10mm is ok.

[Nickfromwales]

6 hours ago, Conor said:

Spoiler alert: 10mm is ok.

 

These Hep2O inserts take very little away from the internal bore, so 10mm will be fine if each rad has a radial supply and none are Tee'd off. Very large towel rads will suffer a little, but it's ok for 'regular' sized ones.

Edited July 27, 2020 by Nickfromwales