"The boiler runs for 15 minutes at minimum
heating output to fill the condensate
trap, the display alternates between
“-II-” and the central heating flow
temperature. This occurs every time the
mains supply has been interrupted."
copied from the manual, link to download it here:
http://www.worcester-bosch.co.uk/cache/file/143/user-manual-for-25--30--35-and-40cdi--discontinued-april-07.pdf
brian
December 2010