Hi all, ive had the potterton combi bolier for 6yr ish now and each year/18mths there has a been a problem, the main board has been replaced twice,theromosats replaced,pressure switchs, one problem that im hopin that isnt as serious as the faults ive had is the overflow pipe outside has constantly been dripping over the last month or so,it even drips when the heating isnt on! The wall&floor outside is a mess and im worried damp is starting on the wall inside the house from the constant drip. Any help please?