I wonder if anyone can advise me on some questions that I cannot find mentioned anywhere on  the web for an simple wet UFH project.

I have just laid a 7-loop underfloor heating pipe system in my (very well insulated)  small 3 floored 3 bed family Victorian house.

I intend to use a combi-condensing boiler, and run the boiler flow heating pipe first  to  two directly in-line conventional radiators. Then return th= at flow to the input manifold for the 4 underfloor heating loops for the
wooden upper floors. (FYI