I am considering installing UFH in a bathroom, the arear to be warmed
is 8 square meters my plan is to run the boiler flow pipe (22mm) to two

zone valves one of which runs the whole houses radiators and the other
is to run to the bathroom in 22mm where it is reduced to 10mm JG
speedfit for the UFH loop and back on to the 22mm return to the boiler.


The boiler is Worcester 28i junior (non condensing) and brand new.

My question is by reducing it to 10mm will this provide sufficient heat
reduction ie
if my boiler gives out 90 deg c will the sudden decrese fromn 22mm to
10 mm
pipe reduce this? so as I dont have the full heat of the boiler on the
floor
tiles?


i.e. I dont want to cause them to crack through thermal shock.


I am a electrician not plumber but have a few years of experience in
domestic heating systems

I am aware that thermal shock is possible the tiles are ceramic and
11mm
thick as for the controls i was thinking that a radaitor valve works on

the principal of closing the lock shield slightly there by reducing the

flow, that is my reason for using 10mm pipe ie the reduction from 22mm
to 10mm would severly reduce flow and temperature.


I could very well be wrong! but i hope not.


Thanks for any advice


Martyn