vaillant combi boiler
Posted: Sun Dec 18, 2011 5:49 pm
hi all i have a vaillant 831 ecotec plus condensing combi, fitted august 2008,now and then it makes a loud buzzing noise like a very large bee is inside the boiler,but when i open hot water tap for a second or two it stops.any ideas to remody this would be appreciated.thanks.