Old 11-13-09, 07:23 AM
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Join Date: Apr 2003
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My house has a gas water boiler with base board heat.I have
no heat at my base board radiators on my second floor.Two
years ago I had same problem and a friend told me he would
bleed the air from the baseboards which he did and the heat worked.I wasn't there so I need your help.First why is air getting into my system? second when I bleed them do I turn the heat off
so the circulator doesn't run or doesn't it make a difference?Thank you in advance for your help
Old 11-13-09, 01:45 PM
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Air can enter the system if it is depressurized and opened for maintenance. Could that be your situation?

Or if you have a leak in the system and continual make-up, air will be brought in with the make-up water.

If you have a bladder-type expansion tank, you need to have a functioning air-removal device, such as a maid-o-mist. And the cap needs to be loose for air to escape.

You can bleed the system first with the circulator off. Then do it again with the circulator on. But there are different schools of thought.
Old 11-13-09, 03:48 PM
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Ron, the first thing I usually ask when folks aren't heating on the upper levels is "what is the pressure gauge on the boiler reading?", and at what temperature?

It is possible that your system pressure is low and not maintaining enough pressure on the upper loop to keep it air free.

So check the pressure gauge, tell us what the pressure is when the boiler is cool, say 100F, and again when the boiler is hot, say 180F.

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