Vaillant ecoTec plus 624 boiler

[KCK]

Hi
Had the above boiler fitted two and a half years ago. has worked fine until yesterday. Yesterday evening the boiler refused to fire up. Without heating last night and this morning. Now it has suddenly started working, though I think there is a slight bubbling sound coming from the boiler.
can you tell me what could have caused this stop /start and is there some inherent fault that needs to be fixed.

 

[Andygasman2010]

More info needed really. At a guess maybe the condense trap/siphon/pipe was blocked....?

 

[KCK]

Not sure what kind of information that you need. Have booked engineer to come tomorrow, will mention the above possibilties and see if these are ok.Thanks for the info.