The pipes to the heat exchanger in this Firebird Olympic combi boiler have joints of a type I am not used to. The pipe ends have a flat flange which fits against a male threaded brass tube like the tail of a tap[1], but unlike a tap connector they have no continuation of the pipe into the tail. They have been made with various versions of fibre washer and jointing compound, but invariably start leaking. I suspect they may be designed to be used without any washer, but the flanges do not lie flat because the copper pipes are not accurately made to lie in the plane of the joints on the heat exchanger. I feel the copper flanges might bend or break if tightened with no washer.
Does anyone know how these joints should be made, and how to stop them leaking? Many thanks for any comments.
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