The covers are there for safety reasons, removing them is not a good idea. The boiler will not work safely without them. It could be VERY dangerous to use it now that the covers have been removed. It is also illegal for non competant people to work on gas appliances as they can and do kill people ,you ,your familly, your neighbours.....are all at risk.
I suspect that the problems you have with your boiler are external to the boiler posibly motorised valve.
However the boiler must be checked by a professional.
I hope this is constructive enough for you.
mrgas
October 2007