Correct me if I’m wrong - but yesterdays usage pretty much shows how much gas the boiler uses to fire up for the HW only (we can see that between 11-1) which looks like
.62m3 from 11-11.30
.34m3 from 11.30-12
.05m3 from 12-12.30
0 from 12.30 to 1 (I’m presuming the water was at temperature and...