Is it okay to use 10mm pipe upstairs and 15mm downstairs?

[henry smith]

I have replaced all my dowstairs pipework using 22 and 15mm copper.

I now want to replace upstairs, but it would be much easier to use microbore.

Is it ok to have two different sizes of pipe in my heating system?

Cheers for any advice.

 

[chrishutt]

Yes it's OK. But .....you may have to close down lockshield valves on other rads (those fed by 15mm pipes) to balance the system, and subject to limits on how much heating load 10mm pipes can carry. Rule of thumb - 10mm fine for all rad connections but pipes serving two or more rads may need to be 15mm (or even 22mm) depending on total load. There have been some recent threads on this - do a search for references to 10mm pipe.

 

[henry smith]

Will do.

Cheers for that.