how to bleed a boiler furnace radiator?
First of all, you need to figure out which one you have. Boiler = water or steam, furnace=forced air. If you have a water boiler and find it's airbound (most common sign is noisy pipes ) you have to go to each register (whether it be a baseboard or radiator) and find the bleeder screw. It will be on the end elbow on each baseboard or on one of the pipes coming up on radiators. Turn the boiler on (turn your thermostat down so it calls for heat) and go to the highest point in the house. The air usually goes there. Take a large pot with you to catch the water. Carefully open the bleeder slowly until you hear air coming out. Stop turning. The next thing you'll see is water spitting. Catch it in the pot and close the bleeder.Wait a minute and repeat. Do this on all of the of the registers until all the air is bled out and the noise goes away. Remember if you can hear hydronic heat flowing, there's a problem! Now, if you dont have bleeders on the registers, that's a headache but can be done. Downstairs at the boiler you should see a valve for a hose. Similar to the ones on the outside of the house.Again with the boiler running and with a hose hooked up to this valve and draining into a sink. Open the valve and let the air and water flow out. Do this only for 30-45 seconds at a time though because you can easily drain the boiler and ruin it. Repeat until sound goes away. Keep an eye on the water pressure gauge-dont let it drop too low! Close the valve and let the water feed fill the boiler again.
