How do I properly "bleed" the cast iron radiators in a home hot water heat radiation system ?

My home heating system is not operating quite as it should. Not bad, not good. I have one radiator that heats on it's lower half and not the upper half. Another does not heat at all. The first/ground floor radiators in my house seem to work just fine and the two problem radiators are both on the second/upper floor. What's going on here?

When I bleed water from a radiator does the heating system automatically compensate for this by taking in new water?

If the water bleed produces discoloured water does this indicate a problem?

Yes! Go ahead and recommend a website that discusses this particular problem in detail if you would prefer.

Thank You !!

5 Answers

  • 1 decade ago
    Favorite Answer

    first of all, is this a steam system? if it is you don't need to bleed it. there probably is a clog. if it is not steam then does the heat make any noise like a gurgling? that is a sign of air. most furnaces will replenish water but to do this faster there is a valve on the water pipe going into the furnace (it will be the cold pipe). the water that comes out will probably be brown. this is rust. you can flush the system until the water comes more clear. this may take several buckets.

  • Anonymous
    4 years ago

    Bleeding Hot Water Radiators

  • Anonymous
    1 decade ago

    !. Shut the boiler off and let system completely cool

    2. Go to the very last radiator and open the bleeder valve, leave this valve open

    3. Go to the very first radiator and open the bleeder valve, allow water to flow out until there is a steady stream.

    4. Go to the second radiator and continue the process

    5. Go to each additional radiator and continue the process until you reach the last radiator. when the last radiator has a steady stream of water coming from the bleeder, close the bleeder

    6. Return to the boiler but do not turn it on yet, Locate the high pressure pop off valve ( High pressure relief valve) and open it, leave this valve open until a steady stream of water comes out of the over flow tube. When you have a steady stream of water let it continue to run out for about 15 minutes to make sure all of the air has been purged from the system.

    7. When you are certian all the air has been purged from the system close the high pressure relief valve and fire your boiler

    8. After the system has built enough pressure to make steam heat locate the jocky pump (circulation pump) and make sure it is working properly. Your problem may not be air in the system, it may just be a bad circulation pump. If your circulation pump has gone bad or is not working properly then you will only get heat to the first one or two radiators in the line. Also if you have a very old heating system scale build up may have clogged the line.

    If you have discolored water coming from the system when you bleed it then you need to flush the system until the water shows clear again. Boiler systems should be flushed periodicly to keep the rust and scale build up flushed out of the system.

    Never ever turn the cold water make up valve on unless you are sure that the boiler is completely cold unless you want to blow up your boiler. Cold water will bust the tubes inside the boiler and possibly cause serious harm to anyone standing close by.

    One last note: Never listen to idiots who have no experience with steam boiler systems unless you like taking risk with your life.

    You also dont have to trust my advice, you can call an Industrial Steam Boiler Company and they will be happy to talk with you on the telephone. If you cant find one in your local telephone directory then call the nearest Manufacturing Company near you and ask the Director of Maintenance to recommend some one who services steam boilers.

    Please post the type and model of your boiler. some systems are hot water systems and some are steam systems the procedure is differant for each. If you have a steam system instead of a hot water system then you will want to flush all of the trunk lines and then make sure all of the water is drained from the radiators and trunk lines before firing the boiler because a water flooded steam system will also only heat the first one or two rdiators in the line

    Source(s): 25 years as an Industrial Steam Boiler Operator and Industrial Maintenance Manager/Safety Administrator
  • bob r
    Lv 4
    1 decade ago

    Not Enough information Is It Hot Water Or Is It Steam.

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  • 1 decade ago

    You don't need a website just read the answer from jojo234 and

    make sure the bleeding valves are not to hot to touch and they are clean from built up paint ect.

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