I called Polypipe tech support line.
They are nice chaps. Talked me through how to turn off the Optimum start / ITCS feature on the thermostats.
I've turned the Lounge one off and will see how it goes now I've put it on 1 hour earlier.
They did not have much of a view on optimum flow rates or...
Over two years after this thread went dormant but searching around I found it and we seem to have exactly this problem!
We have wet UFH in all rooms and a wood burner in the lounge as well. It's a Polypipe system and each room has a wired ITCS / Optimum start programmable thermostat.
We moved...
