Hi not sure whether someone can help or not , l have a laguna and the heater does not work, when l turn the blower on it will only work when it is on no4 setting but still no heat will come out its not freezing cold air but not hot (if that makes any sense) its a P reg in really good order works great , but no heat!! l av been told from someone l could need a new matrix , but was wondering whether it could be something very simple to fix , any ideas would be grateful . thanks .

Should be simple enough for a mechanically capable person, but l would just book it in and let the garage fix it.