Forever Changes
Bluelighter
Yeah, however low you can handle. A lower CH temp (like under 50 but as low as you can manage - even 40C) will be more efficient. For combi hot water (ie not those with tanks, who need to worry about legionnaires) probably 50C is as low as you're gonna want. But the CH uses most of the gas so that's the best one to get low.
Well I never really touch the boiler dials - I just set the thermostat to what temp I want. And if I'm only going to be in one room I'll usually turn the radiators in the other rooms off.
I've just changed both the heating and hot water dials to 50c on my boiler