Different Pipe Sizes in CH System

[Rambler]

Hi,

I've recently moved into a house and was surprised to see that some rads are connected with 15mm while others use 10mm, there is even one rad that has one of each. While I'm no stranger to CH systems and appreciate that di8fferent pipe sizes can be used to maintain flow and pressure, I've never come across a mixture like this before.

Its a 2 storey house and the system has 12 rads working off a Ferroli F30 combi boiler. The rads are what I would consider as fairly standard sizes for the type of house and the room size etc..

The system appears to work OK but it seems odd to be supplying reasonably large rads with such small bore pipes and having to step-up to 15mm to make the connections. Maybe some of you more experienced folk can put my mind at rest.

Cheers
Rambler

 

[Chalked]

Without going not too much detail.

Does it work ok?

 

[Rambler]

Hi,

It appears to work OK but only with everything cranked up to near the max, with really cold weather I'm not sure it will be up to the job. I was wondering if the choice of such small pipes was perhaps restricting the flow to the rads and thereby limiting their performance. I appreciate that the boiler is not a world-beater and if its hampered by a less than efficient pipe system I may need to consider some major changes in the not too distant future.

Cheers

 

[Riley]

All it will do is reduce the KW each radiator is capable of producing

 

[Chalked]

Installed correctly, 10mm copper will carry nearly 10,000 btu. That's quite a big rad! Unfortunatly, most microbore was thrown in.

 

[Rambler]

Hi guys,

Thanks for the feedback. Most of the 10mm pipework in embedded in the walls behind the plasterboard so I can't confirm the quality of installation but I have my suspicions. We'll see how it performs if the weather gets colder.

Anyway thanks for your help.

Cheers