I recently had my chimney relined with a stainless steel liner. Previously there was just brick. Before the relining, the boiler connected to the chimney with a metal pipe, about 7-8 inches in diameter. This pipe had an elliptical hole, about 10" long by 4" or so cut out of the underside of it. When the mason relined the chimney he installed a new stainless steel connection from the boiler to the new stainless steel liner in the chimney, then mortared everything up nicely.

My question is, did that elliptical hole in the original connection provide intake air to allow the boiler exhaust to rise through the chimney? will it exhaust properly without it? and is it normal for the chimney flue connection to get considerably hot to the touch?

Thanks for any help.