In a medium size 3 bed house,would it cost much more to run a 31.0kw 105,800btu boiler than a 23.0kw 78,500one?

I am considering getting a Vaillant Ecotec Plus 831 Condensing Combi BoilerIn a medium size 3 bed house,would it cost much more to run a 31.0kw 105,800btu boiler than a 23.0kw 78,500one?
not really you might even find it costs less, because of the size of the heat output it will heat more water quicker and therefore turn off sooner, plus unless you are adding more radiators they will reachTemperature sooner

red hair