Am having a problem with an Ideal C80FF combi boiler. It goes to lockout in either hot water or heating mode. Pressing the reset works and the boiler functions OK useually for some time(hours or days).
It has been serviced and checked for a specific fault. No fault found and the engineer suggested replacing the thermostat (he may mean the thermister, as the O/H stat has not tripped and has continuity across the terminals, but could not guarantee this would fix it.
I am not qualified to take the combustion cover off but it seems possible that a problem with the fan or pressure sensor in the flue area could produce this sort of fault.
Any suggestions would be appreciated.