How to bleed air from boiler for baseboard heat

Old 10-08-10, 03:07 PM
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How to bleed air from boiler for baseboard heat

Hi, I have baseboard heat but I do not see any air relief valves on the pipes upstairs. I want to drain the air from the system - which has never been done. It makes pinging noises and water rush noises when the heat comes on. Here is a picture of my boiler. I seems like I should be able to hook up a hose to the threaded outlet, open the water in, and then open the valve where the hose is connected until the air is out. There's a relief valve of some sort in the way back. Not sure what that does though.

Link to photo on flickr. Boiler | Flickr - Photo Sharing!

Any help is appreciated. Thanks.
Old 10-08-10, 04:01 PM
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Hooking up a hose to your boiler isn't a good idea. City water pressure might be 60 psi, or more. Your boiler probably has a design pressure of 30 psi. So, let's forget that idea.

It shouldn't be necessary to routinely bleed (not drain) air from a system - unless it has been opened for maintenance, allowing air to enter. You should have one or more air removal devices on your system, although your picture doesn't show them. More photos might help us.

Pinging noises, particulary as the system heats up, shouldn't be caused by air. Probably just thermal expansion and contraction. How hot do you run your boiler? Maybe a little cooler, might help the pinging - but not below, say, 150 deg F for the time being to avoid condensation.

Swishing noises could indicate some air, or mean nothing.

Do all your heat emitters get hot? Then don't worry too much about air. But, do make sure you have one or more air eliminator devices - about the size of a tomato-paste can with a vent valve on top. Photos, please.
Old 10-21-10, 04:37 AM
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I would check to see that there is enough water in the system. My neighbor's system
was noisy and it turned out that his fill valve was plugged up and prevented self-filling.

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