I read all your helpful comments regarding the EA fault message and understand that I should change the PCB. I just couldn't find a description of what that is. Any help much appreciated.
Worcester boiler
Probably greenstar
Goto Worcester website and type "EA fault"
Tells you to check for blocked(or frozen) condensate pipe
Even tells you how to unblock
Q
August 2015
Well done - PCB stands for Printed Circuit Board - the control electronics - you do not say the make & model of your boiler or the fault you're having.
You do not say the category you placed the first question in
Good luck...
July 2015
I have now figured out what the PCB is. Not easy to change on a Sunday. Seems like no hot water today.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.