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suden water hammer

i have a small radiator (4-5 fins) that was installed all wrong. (the "T" off the main is vertical instead of a 45 degree angle, no shut off valve) in spite of that it ran well (and quietly). recently without any changes to my system this radiator started making very loud hammering bangs about 15 minutes into the cycle. i tried increasing the pitch but it is difficult with such a small rad as the whole thing just lifted of the ground. i understand that i should probably pay to correct the issues, but i would rather not shell out all that $$$ right now.


  • Kool Rod
    Kool Rod Member Posts: 175

    I'm assuming that this is a 1 pipe steam system. If the pitch is okay, you might want to check and see if the valve on the inlet pipe is fully open (and isn't broken). It has to be either fully open or fully closed! If it is partially open, the steam going into the radiator and the water (condensate) leaving the radiator, try to get through the half open valve and collide, causing water hammer.

    Another possibility is there might be a "sag" in the pipe going from the radiator to the main which would cause a pool of condensate (water) to collect. When the pool has collected enough water to interfere with the steam flow, you would get water hammer.

    - Rod
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