expansion tank

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    • #275474
      piegie

      The heating guy who replaced a radiator in my house drained the whole system and refilled it when he was finished. He bled the system from the expansion tank until water came out the air valve. After he left, the upstairs radiators didn’t work, so I bled them myself(alot of air came out).Now everything works, but if I press the needle on the expansion tank air valve, water comes out. Is this normal? If not, what can I do to correct it? Thanks.

    • #292211
      Harold Kestenholz
      Participant

      If the tank is a proper heating expansion tank with a diaphragm, only gas should come out of the needle valve on the bottom of the tank (and it shouldn’t be fooled with or there will not be the proper pressure to do the job.) Water indicates that the diaphragm is cracked and the tank needs replacement.

      If you are talking about the small canister on the top of the air scoop above the tank, that is an air vent and water will come out now that there is no air in the system. Much water removal this way will lower water pressure and permit air to enter the system. Read the air purge procedure at http://www.hydronic.net for a fuller description of what is happening.

    • #292212
      SylvanLMP
      Participant


      In reply to message posted by Harold Kestenholz:
      If the tank is a proper heating expansion tank with a diaphragm, only gas should come out of the needle valve on the bottom of the tank (and it shouldn’t be fooled with or there will not be the proper pressure to do the job.) Water indicates that the diaphragm is cracked and the tank needs replacement.

      If you are talking about the small canister on the top of the air scoop above the tank, that is an air vent and water will come out now that there is no air in the system. Much water removal this way will lower water pressure and permit air to enter the system. Read the air purge procedure at http://www.hydronic.net for a fuller description of what is happening.


      Harold your GREATTTTTTTTTTTTTT as Tony the “TIEGER” would say.

      Now you can fully understand why I do not care for the trol tanks where a bladder can rupture and cause wacky out of control pressure.

      At least with the older type all one had to do was drain it.

      About the scraider valve on the so called automatic air eliminator this is why I use the Hoffman 75 or Spiro vent that removes even Micro bubbles rather then the beer can type cheaper model 77.

      The schraider valve is prone to failure with any debris or even failure in the closed position due to rusting or particles blocking the orifice.

      I am impressed how you guessed the system parts KEEP up the fantastic job your doing kind sir

      Of course a lot of the heating *********** would never think of paying upwards of $100 for just an air removal device huh?

      HAVE A GREAT Holiday

      » This message has been edited by SylvanLMP on 29 March 2002

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