this is a very dangerous senario, as you know this hole could allow products of combustion to enter the room, im assuming you have an old style boiler without a fan, ive had to condem a potterton kingfisher open flued boiler this week for the same problem, we tried to source replacement parts, the son of the customer tried to weld it but too decayed, in the end you cant take risks in a situation like this, fire cement is definatley not an option, new boiler im sorry to say
john, February 2010
