Air in the system


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Old 01-10-09, 12:32 PM
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Air in the system

How to get rid of air in the hot water based heating system? Thanks in advance.
 
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Old 01-10-09, 12:47 PM
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Short answer for a short question:

Bleed it using the air bleeders on the radiators.

Longer answer requires much more information.
 
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Old 01-12-09, 05:50 AM
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There are no radiators, only baseboard. There is an air vent near the expansion tank. I would assume the air, if any, should goes out from the vent by itself, right?
 
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Old 01-12-09, 11:19 AM
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Originally Posted by jago60
There are no radiators, only baseboard. There is an air vent near the expansion tank. I would assume the air, if any, should goes out from the vent by itself, right?
Then bleed the baseboards. Hopefully, there is an air bleeder on each of the baseboards.

Can you post a photo of the expansion tank and the vent that is "near"? What kind of expansion tank do you have? The bladder type (looks like R2D2) or a conventional tank (typically hangs from the joists)? If you have the bladder type, and you are referring to a schraeder valve on top, you certainly don't want to vent air from there.
Doug
 
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Old 01-12-09, 04:51 PM
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Baseboards are 'radiators' too... at least partially... they are also 'convectors' ... but standing cast iron radiators also convect... anyhow, I was using that as a generic term. Would it have made more sense if I had said 'emitters' ?

Sometimes when there is air in the system it is a SYMPTOM of some other problem... such as low pressure in the boiler.

You need to tell us more... for example:

What is the pressure in the system when cold?
and what is the pressure when hot?

Why do you think you need to bleed air? Is it because you HEAR air gurgling around? or is it because some of the baseboards are not heating up?

What seems like an easy question never is...
 
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Old 01-13-09, 08:12 AM
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Because of the noise comes from the pipes, also a splash sound when the heat cycle is off. The boiler pressure is around 7 psi, both hot and cold. I have an Extrel tank. How to increase the pressure easily? Thanks again.
 
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Old 01-13-09, 04:53 PM
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jago, the pressure of 7 PSI is very much too low for the heating system, and this is most likely reason that you have air in the pipes.

The first thing to know is if the pressure GAUGE is reporting the proper pressure to you. That gauge may very easily be defective. If the pressure reads 7 PSI at all times, I am quite sure that the gauge is defective.

Before anything else, the gauge must be verified to be accurate. Only then can any more help be offered.
 
 

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