Greenstar Ri Worcester Boiler - Help!!?

Our heating came on fine this morning but when the evening start time came round the green light came on but the boiler then started to stop and start and now the blue light is flashing every two seconds.

Have been reading with interest that the problem could be the condesate pipe but am a lady going it alone here so want to be sure I'm doing this right!

Firstly, do I have to turn anything off (i.e switch of at mains and will I then need to reset everything?) before I start?

Secondly, if I remove the underneath of the boiler in order to fully access the pipe is it simply a case of unscrewing the white plastic bolt looking thing holding the pipes together?

Finally, does the condesate pipe lead outside? I have a pipe which comes out on the other side of the wall to the boiler but always presumed this was simply an overflow pipe.

Any further help would be much appreciated. Gotta get this right as I have two little-ones here to keep warm!

Kate