Whats the best temperature to keep an oil fired boiler at, stat goes from 60 to 80?

Usually not below 65 and a NO NO for 80.


You require hot water for domestic purposes so 65 is just fine.


Oil fired boilers are similar to cars, if you drive at 80 you will use more fuel than at 50 same goes for boilers


The consumption of fuel rises exponentially as you increase the temperature., so it makes good sense to keep the boiler as low as is comfortable.