Went to one the other day to service, noticed the hot water wasn't very hot. Didn't really have time to properly investigate but struggling to get more than about 8ltrs/min without it going tepid. B.P fine, not modulating or cutting out but heating flow didn't feel like it warmed up at all either, although the heating had been on before I got there. Any other ideas before I investigate further? Can only presume its creeping past down the heating slightly so only getting 80% or so to water.
cheers in advance
cheers in advance