UFH low flow rates

[Nickfromwales]

16 hours ago, dpmiller said:

What size of pipe is that at the front left of the mixer?Please tell me it's *not* 15mm...

Well spotted, eyes like a bloody hawk!

 

15 hours ago, SamKeen said:

Feed and return are 22mm but they reduce to 15 just as they enter the manifold

Why they did this is beyond me.  . Needs to be 22mm, but if up to temp it shouldn't matter that much. From a cold start is where this is most relevant.

[Nickfromwales]

9 hours ago, SamKeen said:

That sounds like a good idea aswell. Cheers mate I’ll order some tonight 

Have you opened the mixing valve all the way up and checked if the flow rates perk up then? At low temp settings those types of mixing valves strangle the flow a lot.