I have a Greenstar Worcester 42I, I got an with the EA error code this morning with overnight temperatures reported as low as -7C. It turned out the Condensate pipe was frozen, three kettles of boiling water later I have a perfectly functioning boiler again. Thank you for the forum and those whose post up the answers. I hope my answer will help others in resolving their boiler problems.
Jeeves (Leicestershire), January 2010