I just had a 200,ooobtu steam boiler installed. When the water heats up the boiler shut off and the water leaves the boiler running back into the return line and floods the radiators on the lower level. Then the automatic water light comes on and the boiler is looking for water, to replace what has left. We have to keep a shut off value on to prevent more water feed the boiler. If we don't the entire house would be flooded. The water does return back and the cycle being again.
I have talk to 5 different plumbers about this problem. Just in case you ask what about the guys who install it. DON'T. TOTALY CLUELESS.
Any way, my return line from the main was 1 1/4" copper and was reduce to 1". Never had a problem like this with my old boiler. I was told that my return line should be all 1 1/4" black pipe. So we changed it, and nothing change. And if you ask the question did I have it skimmed (YES). We remove all the oil from the boiler/pipes.
Its like some type of pressure is pushing the water out as the steam goes up
Does anyone have suggestion as to why this could happing and how to fix it?