been to look at another motorhome today and found that the water heater is shot ,is it possible to get another newer water /space heater that wil go back through the same flue hole on the back of this motorhome there are lots off like pimples which have been covered with some sort of tape does anyone know why these pimples appear , I assume the back panel is some sort of alloy it is a k regd swift capri any help appreciated