We had a new boiler fitted and because of its location, an airing cupboard on the landing, the condensate pipe was run up into the loft and then into the down pipe. The alternative, when they thought that they may not be able to do that would have been to run it through the loft and into the corner of the bathroom, joining the waste pipe under the wash basin. This year's awful experiences might encourage heating engineers to avoid an outside pipe if possible.
Good luck with solving your problem and all the others suffering similarly.