There is an overheat reset button top left inside combustion chamber.
Now thats exactly the advice which I dont think we should be giving on here.
Thats a clear encouragement to the DIYer to open up the combustion chamber.
Clearly only a CORGI should be opening the CC and furthermore should be investigating the cause of the overheat.
If thats being said then as a MINIMUM it should be qualified by saying it should only be opened by a CORGI.
Tony