My boiler is starting to knock and bang. I have three zone baseboard heat, with spigots for each zoneto bleed the system right on each main line, just above the boiler. My question is - Does the boiler have to be fired up when I bleed each zone, of can I do it when it's cold? How much should I bleed from each zone?
There should be a valve on each baseboard. Start at the closest one and bleed out until all the air is gone and water starts to come out. Then go to the next baseboard and do the same, and the third. It doesn't matter if the boiler is on or not. But you should bleed the system at the baseboards, not the boiler. If you just do the valves by the boiler, you won't be getting the air out of the system. If there isn't a valve on each baseboard, there will be one on the furthest one just before the water returns to the boiler. Remember, the water will be hot so don't get burned. It may take a couple of times to get all the air out of the system but you can do it. Good luck.
yes bleed while its fired up..you want to bleed it to the point where there is a constant stream of water...bleed lets say a cup of steady water flow,..
