Loss of hot flow in kitchen mixer - bungalow!

[DIYOX3]

I have installed a new Franke 1/4 turn kitchen monobloc mixer tap. All 15mm copper with service valve. Hot flow was a trickle so I removed the flexi hose on the hot side, replaced with copper all the way to mixer tail. Slightly better, but still unacceptable flow. This is in a bungalow with probably no more than 2½m head !!? BUT bathroom basin tap on 15mm has a much better flow. I am going thro it in stages to isolate the problem (bypassing joints/valves etc) but feel it will be down to the much restricted diameter where the 10mm (max) hot tail joins the mixer body combined with the low pressure of a bungalow? Please don't suggest moving header tank, it has been fine for years on conventional taps....HELP... suggestions please. DIYOX3

 

[gas4you]

Your new mixer is probably designed to work on mains pressure rather than a gravity fed hot supply. Most 10mm fed taps are.

 

[DIYOX3]

Your new mixer is probably designed to work on mains pressure rather than a gravity fed hot supply. Most 10mm fed taps are.

Thanks but few households have pressured hot and there must be plenty like this, many have mixers and gravity feed, what do they do? Should I be looking for a blockage in mixer, swap check valve for gate valve (full bore? Or is there a monobloc mixer with larger feed diameter directly through tap body?? I do think it is partly this specific mixer. Will ask neighbours if they have mixer + problems, will also speak with Franke

ANY suggestions please to make this acceptable.

Thanks

 

[TicklyT]

Your new mixer is probably designed to work on mains pressure rather than a gravity fed hot supply. Most 10mm fed taps are.

Thanks but few households have pressured hot ..........
Thanks

Almost everyone with a combi boiler has a pressurised hot water system...

Unfortunately, most monobloc mixers are designed for pressurised systems. There's not much space inside them for decent sized waterways required for gravity systems.

A 2.5 Metre head equates to about 0.25 Bar. What does it say in the instructions for the mixer?