Suprima HE not switching on ?

99% of the time the boiler is fine but occasionally refuses to switch back on when the 'stat calls for heat. I've found the best way to deal with it is to isolate the boiler from power for 30 secs. to 1 minute then switch back on & all is well.
My question is; is this a for-runner of impending control board doom or is it merely a board glitch.