We turned on boiler for first time last week, ran for a while, turned it off ourselves. (We're holding out as much as we can until we get our pellet stove in a couple weeks.) Turned it on again last night and it's not working. The red lockout light is on. Pushed to reset, it fired up and then shut off again, with light on again. We did not run out of fuel and the water level appears to be fine. I tried to bleed it anyway but the nut is on too tight, my husband must have been the last one to bleed it, he always overtightens. Any ideas?