I made my mind up to replace my existing 8mm microbore with 15mm speedfit and bought all my fittings, etc... Now one of the bedrooms upstairs, is small, the radiator is tucked right into the corner to allow a single bed..., on lifting the floorboards its impossible without destroying joists as theres two sepaarate joists in parallel running opposite directions, and I'd have to take half of one away, to use 15mm, the previously installed 8mm could slip through them... A few plumbers have said to me to use 10mm behind the radiators, for ease and it looks tidier, but I wanted to stick with 15mm for a better flow... Should I just go for the 10mm and bring it up behind the walls instead of the 15mm? Can I have 15mm to some radiators and 10mm to others will this have any detrimental affect, like balancing ?? Also I've bought Drayton TRV4 valves for the 15mm, can I use these elbows to convert them to pushfit http://www.screwfix.com/p/pegler-push-fit-elbow-10mm/28509 , or will I need Drayton elbows? Thanks
its my bedtime, so i have not bovered to read all of your post. yes, you can use 10 & 15mm and it will pose no detrimental affect, like balancing??