Mine is an eight year old Worcester Bosch and that only goes to DHW 60 degrees. I think a lot of the new boilers only go to that now. It’s probably down to environmental and green energy saving stipulation trumped up by the EU…
I've done a bit of digging regarding the pre heat option and extra cost.
Apparently some of the newer combo's have a pre heat timer rather than having it on 24/7.
One guy measured the gad usage with pre heat on for 24 hours and off. It worked out at £50 extra for the year but balance that against the water wastage waiting for hot water to come through I can't see it been a massive wastage.
Anyone got any suggestions on a combi with pre heat either with/out a timer for a 3 bed property?. I had a Vaillant but tbh it was good when it worked but it conked out quite a few times till it completely died.