just moved in to new'ish place, wall stat drayton does'nt click when
heating on, water not getting very hot although radiators with stats
working ok, temp and water set ok. 5 valves 4 isolating cocks
underneath boiler any idea what position they should be in ?

So your problem is that the hot water from the tap isn't very hot?

It might be related to the fact that you have a 24kW combi, which can only
support a quite pathetic flow rate before the temperature starts dropping.
Try running at more of a dribble to see if it gets hotter.

Christian.