EA is ignition lockout, this means that something in the boiler's startup sequence has gone tits up. It could be down to something silly like gas pressure being too low (not something you can check yourself), it could be a problem with combustion (not enough air - there is a flap valve in the fan that can cause this), spark not being strong enough to get things lit (or even mistimed). Can even be a flue fault if the boiler cannot get rid of its exhaust fast enough.
The only things you CAN check as a householder is that the flue terminal is not obstructed, that you definitely have the gas on (check your gas fire or hob works OK) and also that the condensate drain for the boiler is not blocked up as this too can throw up EA faults.
Bunslinger, March 2009
