Changing Boiler?

I currently have an old combi boiler in the place I am renting. Bath takes 45 minutes to fill so dont bother often. Landlord is replacing boiler by a Potterton Condensing one - Plumber says there is lots of scale in the combi boiler. Will this make a difference to my running costs significantly (extremely high) and also would the pipes need to be changed also running to the bath or would the boiler change help enough.