OK - so the issue was in the boiler configuration - parameter 933.6 "Operating mode of heating circuit 1" was set to 4 "Weather compensated without room temperature influence". Changing this value to 7 "Weather compensated with room temperature influence" sorted the issue. Parameter is...
Any ideas as to why the burner is on and providing heat to the central heating even though the viessemann thermostat is satisfied. Room temp is showing as 15c and the stat is set to 10c - but burner is on with a flow temp of around 23c. Stat has been set at 10c for over 24 hours for all the...