Boiler uses 2.7m3 of gas per hour.
Run it for an hour a day. Gas used 2.7m3
Run it for 10 hours a day. Gas used 27m3
Don’t agree,
If you have decent thermostatic temperature control and you have your boiler on for 12hrs a day or 24hrs a day you are still only overcoming the insulation losses of your house.
The only difference being if outside is 5degC and inside is 22degC the delta T is constantly 17degC if the boiler is on 24hrs.
If you run the boiler for 12hrs per day, the delta T will drop from 17degC to maybe 9degC (Temp in house after 12hrs 14degC)if your house is fairly well insulated.
So the difference becomes the heat loss difference between 17degC (on 24hrs) and an average of 13degC (on 12hrs) delta T which I would have thought is very little. And of cource this diference in delta T only occurs for 12hrs anyway usually during the day when its warmest outside (when you are at work)