We've come home tonight to find our Vokera Unica condensing boiler leaking too! Is yours a condensing boiler?
If it is, then we think this might help http://www.vokera.co.uk/common-winter-boiler-enquiries/
With such low temperatures (-10 tonight) we think our condenser pipe has frozen and so the drips that would have been directed out the pipe and into the ground outside can no longer escape from the boiler. The leak has alerted us to the problem before the shutdown/errorcodes that vokera mention have occured.
We've dried out the pool of water we found when we opened the air box (the silver box held closed by two clips) so the drip has stopped and tomorrow we're going to try defrosting the pipe and the ground outside as Vokera suggest.
Jo
December 2010