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boiler turns on but radiators don't get hot and bang loudly

Twiggy
Twiggy Member Posts: 6
I am a first time home owner and don't really know much about heating systems, I have a very old boiler system and have been having a lot of problems. When I turn the heat on the boiler fires up no problem but after a bit it sounds like someone is hitting the pipes in my house with a huge hammer. The boiler will run for close to an hour before this starts to happen. The boiler will run but the radiators do not seem to get even warm. Does anyone have any ideas on what the problem might be?

Comments

  • lchmb
    lchmb Member Posts: 2,997
    How

    about some pics? sounds like you have steam heat but it's hard to offer idea's when one's not sure...
  • Twiggy
    Twiggy Member Posts: 6
    ?

    What exactly should I take pics of? I know that the boiler is an arcoliner. I have a pic of what I think is the pressuretrol on my phone but that is it right now. Let me know what you would like to see and I will add more.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    Sounds like steam....

    Pictures from afar of the front, sides (both) and back of the near boiler piping would be beneficial.



    ME

    There was an error rendering this rich post.

  • Twiggy
    Twiggy Member Posts: 6
    ok...

    So I have been doing some research online while at work and from what I can gather I have one pipe steam radiators. I think I am having a pressure issue. Last year I was having a problem with the boiler not turning on and it had to do with the low water cut off. I think my problem now is with the pressuretor. Does that have power that runs to it? If so how much power should it be getting so I can test it when I get home? What I have read is that is it should work with only psi but I don't know if I am even getting that. The pipes in the basement running off the boiler get hot as hell but the radiators up stairs don't get warm at all and just bang. Any ideas?
  • arcoliner

    if the pipes in the basement get hotter than hell, then the boiler must be producing some steam. only a few ounces of steam are necessary to heat the radiators, and any gauge you may have will not be accurate for a diagnosis if it is an excess pressure problem. excess pressure wastes fuel, and can cause the air vents to stop working.

    the steam may not be getting into the radiators because the radiator valves are not completely open, or the air vents are blocked. have the radiators been painted? if so the holes in the vents may have been painted shut. they can be opened up with a pin. if there is no apparent blockage in the radiator vent hole, then let the system cool down, and with the aid of an assistant manning the boiler switch, unscrew the vent, and fire the boiler. be careful not to get close to any escaping steam. see if the radiator gets hot, then have the assistant turn off the boiler, and when cool, replace the vent. report the results here and we can advise the next test

    you should not try this test without a helper ready to turn off the boiler, as escaping steam, besides being dangerous, can remove wallpaper in a few minutes..

    getting some of the steam books here from the shop would enable you to diagnose many problems with your system, and fix many of those problems yourself.--nbc
  • Twiggy
    Twiggy Member Posts: 6
    internal syphon

    What should the internal syphon gauge read when both hot and cold? It goes from 0-30.
  • Twiggy
    Twiggy Member Posts: 6
    think i fixed it

    Ok.... so I think I fixed the problem I was having. The one radiator that was making the banging sound the most I took the breather valve off while I was running the boiler and it was spitting out a tone of water. Probably about 10 gallons all together. Now that there is no water in the system the heat seems to be working much better and without all the banging.
  • Jamie Hall
    Jamie Hall Member Posts: 24,490
    Bravo!

    Be sure to replace that vent, though -- it's a safety feature as well as a control.



    And, now that you have done that, you are ready -- if you want to -- to start improving your system.  The place to start is the pressuretrol.  This has two settings (from the picture it looks as though the cover is off -- is it missing?  That will make this more difficult...).  One, on most pressuretrols, is the cut in, and the other is the differential.  The cut in should be set, for starters, at 1, and the differential also at 1.  See if that makes any noticeable difference...  You might also see if you can find the model number of the pressuretrol.



    You asked whether the pressuretrol has power to it; it does.  It should be in series with the low water cut off. 
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
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