drain sum water from your c/h system and check the colour of the water it should clear or as close as possible if dirty try adding sum sludge remover for a week then draining off again, worse case senario you may need a power flush if it is really blocked or redish water but explore everything else that could cause a problem 1st and check it again as power flushing is not cheap. maybe best to get a reccomended corgi opinion
STE, April 2009