I have been thinking about taking advantage of the new boiler scheme grant and am looking at replacing my existing oil boiler with a new condenser boiler, my current boiler is outside in a little boiler house, if i was to go ahead with replacing the boiler would there need to be any work done inside the house or is it just a matter of removing the old boiler , boiler house and the flue and connecting the new boiler to the pipes that come out through the wall and wire up the new boiler?