how to simply fix problem with worcester combi boiler?

have recentley had new boiler fitted by british gas all was well and then had to get engineer out due to noise combi was making all well again untill this morning reset button keeps flashing as does the mains on/off indicator+fault diagnostic light have pushed reset button it all seems to work for a very short while and then goes back to flashing again and again and again is there a simple solution before we call british gas again