Curious what temperature everyone has their thermostat set to… and do you keep it on at night too?
Also:
Got mine set between 5 & 6 no idea what that means but it seems to be warm enough. I turn mine off at night & put it on when I get up,
C/H is gas warm air.
Easily answered - no central heating. And the wall mounted electric heaters in the upstairs rooms are too expensive. So I fire up the large wood burner in the morning; by lunch time it is warm enough in the main room to open some doors and let the heat through the house. This means the bedrooms are pretty chilly all the time - perhaps 10-12 deg C. I sleep better with cool air and a very warm bed. But it does become a bit testing with nights like this coming week - mostly negative 3 or 4 deg.
Since utility bills are insane here in CA, I don’t set my thermostat at a certain temperature unless I have company. I turn the heat on when I’m going to do anything in the kitchen & when I’m in the shower (along with a space heater), then I turn it off when I’m done. I dress warmly in heated vests. I’d rather spend the money on clothes that I’ll have for years than paying crazy utility bills each month. For sleep, I dress in thick polyester & use two blankets.
When I have company a few times/year, I set the thermostat on both air conditioners at 73.
A lot depends on type of boiler and hot water pipes behing the walls. We have what is called microbore piping so a combie boiler is not the ideal. It could pump too much pressure on the pipework and blow apart a joint. Also a good idea to have a filter to catch any sluding in the heating system. We have just had one fitted to comply with regs. This after having the whole system pressure cleaned out done professionally. I was surprised how much acculimated sludge was within the pipes.
As for how hot to keep a house and for how long? This is a highly variable question. First what your heating up, just radiatiors or/and towel rails. If you going skinny dipping in an ice cold bath or trying to go for a sauna. 
the area your trying to keep warm is a viable consideration let alone how many rads to heat up and their position
One tip we are using is heat shields between rads and wall to reflect heat outwards and not into an outside wall.
Bleeding rads helps by releasing air pressure via loosining up a plug at the side/top an hear the air hiss out
as for actual temperature the answer is what you happy at and cost of heating,there is no def this or that to the question but using a timer cuts down heating bills
We keep it 20C. If it gets warmer than that (in the summer for example) the thermostat automatically shuts down. No action required.
