remeha avanta plus 28c

[notagain104]

Recently I have started up my remeha avanta plus and it has started to bang once after 20 min from starting up and then another round about evening, I looked in there the other day and caught it when it banged and a flame shot out at me I have had a gas safe plumber check it out and he says there are no gas leeks.
Anyone have any ideas what the problems is?

 

[gas4you]

Where did the flame shoot out from exactly?

 

[Boilerman2]

Sounds like you should get it checked by an engineer with a Flue gas analyser and who understands pre-mix burners, I wouldn't use it untill it it properly checked, these are normally excellent boilers, so I am suprised to hear of this problem (mine is purring away nicely on this cold evening)