I have an oil fired Worcester 20/25 Heatslave boiler. Hot water is always scalding hot and turning temperature control on the front makes no difference. Also central heating cuts out (lock out has not tripped nor has overheating switch) sometimes when cold first thing in the morning, sometimes after having been running perfectly OK for a couple of hours in the evening. It will fire up again when it feels like it. Only thing I notice is that the pump is incredibly hot. No strange noises coming from anywhere and system has been flushed and bled. Any suggestions welcome as threats of physical violence to the boiler have also failed.