Over the summer I havent had the heating on. But if the heating is not on there is no hot water. So I have just been pressing the 'boost' button which heats the water (stays on for about an hour?). Can anyone tell me...is this much more expensive because its a boost? Would it be cheaper to have the heating on? Thanks.
If it's the normal thing, boost just means 'stay on for only 1 hour'. It doesn't work any differently to turning your system on for 1 hour and doesn't use any more energy than an hour's normal use.