Air keeps coming back into radiators


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Old 12-30-06, 10:03 AM
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Cool Air keeps coming back into radiators

I bleed the raditaors on my old hot water sytem and after several weeks the air returns and it is very noisy. Any ideas as to what the problem is. The air is coming in from somewhere???Thank you Guy
 
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Old 12-30-06, 01:34 PM
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Expansion tank failed? Water pressure too low?
 
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Old 12-30-06, 01:39 PM
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Wink

What is the psi or how many lb. There on the boiler gauge on the boiler???
 
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Old 12-30-06, 01:39 PM
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bleed again?

Trapped air may be working its way through the system and reaching places where it can be bled. Did the pressure drop since you bled you the system? Try bledding again, and add fill water to bring the pressure back to where it was.
 
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Old 12-30-06, 02:31 PM
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Expansion Tank Style?

What kind of expansion tank do you have? Is it up between the joists above?
 
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Old 01-01-07, 06:39 AM
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Thumbs up WHO's ok in my book!

Originally Posted by Who
What kind of expansion tank do you have? Is it up between the joists above?
Good call WHO! I didn't think of that. Another thought though. How many floors do you have? What is the pressure on the boiler? If you have 3 floors with only 12 PSI on the boiler, a leak on the third floor (or bleeding a radiator up there) would pull air in because at that height, the baseboard would be in a vaccum. Also, what is the aquastat set at? Are you making steam? Do you hear a bubbling sound just after the burner stops firing?
 
 

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