Potterton Suprima boiler lock out - flashing red light

[Redcats100]

I have a customer with a Potterton Suprima boiler that keeps locking out with a red flashing light. If you reset the boiler it fires up fine and heating and hot water work etc and then it just locks out again after an hour or so.

Everything looks in order and flue is clear, customer had a new PCB board put in a a good few years ago, nothing obvious is broken or needs replacing.

Anyone had an experience of what the problem could be?

 

[Deleted member 120897]

If it’s just the red light flashing, then I’d say an overheat situation. So, motorised valve, pump, lack of water etc.