Hi there, just back from a weeks vacation and we have no hot water. (the bar was low so I added water with the black valve, it then went too high so i released water from a couple of rads, it is now just over 1) the boiler is trying to kickin but the usual gas fireup sound is not happening. i look in the little window and do not see a flame, does this mean the pilot light is out? can i restart it myself? cheers