It is a Service Code usually, reminding you to get the boiler serviced every 12 months. I recommend you get it serviced or check your boiler manual to see if there is a method of clearing it. (There usually is)
Mark G
January 2009
I can answer this question...
what does fault code SE mean on my worcester boiler?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.