There's a search box on this page and on Google search - several people guess - one says take out the fuse and put it back and that will fix the problem - ho-ho-ho.
The general consensus is the fan and its associated air pressure switch. Typically with all boilers they will not fire up until the air pressure switch is operated - indicating a working fan and a properly sealed enclosure
Can you hear the fan running?
Good Luck..., September 2015
