you just turn it off with the switch which has a 1 and o on it to the right of the boiler, and then turn it back to on. The indicator will indicate your pressure at about 0.2 to 0.3 or thereabouts.
Under the boiler to the right, if you put your hand under that or look underneath you will see a blue knob. just hold it a bit firm in the middle and open it and you will see the pressure climbing and your boiler will start. When it reaches 1.0 you can shut the valve and it will stop the pressure loop again and everything will be fine.
I am having terrible problem and two tiny prickholes have appeared in the housing unit to the left of the thermistor and have gone through 3 plumbers and having to wait for 9=-10 days currently to get replacement part and tomorrow it is supposed to arrive with the plumber....God help me!!!
Good luck
Justis4u
March 2011