I've had X400 in for 2 weeks now. It seems to be working, and I've run the heating hot at times during cold snaps, including with one radiator at a time. However, at this time of year the heating is off during the day and not that much at night either. I could drain it now, but want to get the most out of it before inhibiting for winter. Would there be any point in running the heating with the back boiler on either setting 0 or 1, so that I get more circulation with the cleaner in, but at low/cold temperatures? i.e. which is more important for getting the most out of x400 - more flow or hotter water? Thanks