If you were told that you may need a new boiler, before the engineer looked at it, then call in another engineer.
If he lokked at it, did he show you what the problem was - I take photos if the customer is not on site.
The only reasons that I can think of for replacing a five year old boiler is that the heat exchanger is beyond repair, which is most unlikely, or that the water caused so much damage that it is beyond viable repair.
TheHeatingMan, April 2010