just had a new combi boiler fitted. the plumber said that if i set the heating temp on the boiler to the max i.e. 82c I wouldnt be using any more gas than if I set it to a lower temp.....
My combi boiler idles at just under 50 and goes up to about 65 when the water is running - and it's very hot, I wouldn't like to see it at 82. I've saved a packet on my gas bills since I had my combi fitted.
Surely you would use more gas though? I have definately used more gas this winter than I usually do, mainly because I've had the heating on full blast for the past 3 months!
It is generally the case that you will use less gas with the boiler temperature turned up.
This is because oil/gas boilers are at their most efficient running at a higher temperature (the implication of this is that a greater proprtion of heat generated disappears up the flue at a lower temperature).
Bearing in mind that the majority of gas used in the winter services the demand for the CH (not domestic hot water) running the boiler temperature at the higher figure will result in less boiler cycling (means when the boiler keeps going on and off in short intervals).
That is the logic.