Tim Lamb wrote on 24/03/2018 :
:-) I have just fired up a 30kW Viessmann in the cottage. I'm not yet
familiar with the controls. Weather comp yes. Different temps. for hot water
and heating, yes I think. You can certainly switch off the heating for
summer. Clear display.

I cannot seem to see a name for the independent boiler output
temperature limiting - anyone, what is it called?

Is it available on a regular, open vented boiler?