Alpha Boiler CB24 Fault

[Humph]

Hi all, I have a Alpha Boiler CB24, approx 7 years old. For the last couple of years I have had an intermittent fault were, when the heating comes on or the hot water is run the boiler fires up and orange light comes on as it should but only for about 5-10 seconds, it then switches off and on 3 or 4 times before it stays on. Boiler is serviced every year but engineer can never find anything wrong..
Any advice would be appreciated..

 

[plumbplumb]

Does it ever go to a fault code? The neon lights A and B flashing in different sequences represent different faults.

 

[Humph]

No never.

 

[Humph]

Only thing i have noticed is that hot water has started to take longer to get to boiling ..