Reset light flashing 4 times/sec and blue light flashes 1/sec. Think in ignition lockout as no flame.switched off/on and fan operating initially until reset light comes on.serviced 4 weeks ago. Most likely fault or any way to get flame back on please as no heat or water. Boiler approx 9yrs old
is it a GREENSTAR 28i junior? [red & blue light]
you mentioned the FAN was working
does the boiler SOUND like a kettle boiling when trying to start up?
IF YES then condensate could be blocked
if external [of boiler] condensate pipe blocked then there are plenty of YOUTUBE guides of HOW TO UNBLOCK FROZEN CONDENSATE PIPES
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.