Central Heating Won't Work

[Vic]

Mine's more mysterious - boiler comes on, runs OK for half an hour, then cuts out, and after several hours cuts in again for a few minutes before cutting out again.

 

[yeseye]

Mine's more mysterious - boiler comes on, runs OK for half an hour, then cuts out, and after several hours cuts in again for a few minutes before cutting out again.

Diverter valve as @remember arthur mann says is almost certainly kaput.
The guy knows his shit.

 

[Vic]

Mine isn't a combi