I'm about to have a new oil boiler fitted and have been given the choice between internal and external. Because going external would free up some space my wife would prefer that option, however, having read of various cold weather problems suffered by combi boilers in general over the last few winters I'm looking for advice as to how the externals cope. In particular in v. cold weather does the anti frost stat permanently trip(thereby using more fuel), is there a greater problem with condensate freezing and is there a noticeable loss in efficiency in general in extreme weather. I've spent the day searching various websites but can't find the answers so hope DIYnot members can help. Any thoughts would be appreciated.