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Pipes Banging/Water & Oil Spurting from Radiator Valves

Had a new boiler installed last March.  I have had to call the installer back repeatedly to drain the system.

Radiators are holding water, pipes are banging and there is water/oil spurting out of the valves.

I have read that the pipes can cause this issue, so I am wondering if you can take a look at what my installer did. 

The new boiler is a Smith Cast Iron Series 8 Boiler.


  • HenryTHenryT Member Posts: 128
    Not a professional

    Let me state that I am not a professional but a long time lurker on this great forum. From the initial looks, it seems as if your header is too low. Your riser pipes off the radiator could be longer and should extend at least 25" from the boiler water level.

    I am half way out the door so I have to keep it short. Your near boiler piping in HORRENDOUS. You really deserve a refund. This one is one for the the record books (or maybe "The steamfitters book of jokes")
  • Big-AlBig-Al Member Posts: 263
    edited November 2010
    Header Wrong

    Yes, the header is definitely wrong.  The pipe coming up out of the top of the boiler should go straight up, at least 24" above the normal water line.  It should then go straight across horizontally to a downward flowing vertical pipe (equalizer) and drop back down into the boiler below the water line.  Somewhere in the middle of the horizontal part of that header, there should be a tee and a vertical pipe to carry the steam upward to the main. 

    There isn't much space above the water line in a modern boiler, so the near-boiler piping is an essential part of the boiler itself.  In a modern boiler, there is always some liquid water carried along with the steam out of the boiler, and the piping needs to return it to the boiler.  .  You want the liquid water to slow down and drop to the bottom of the header, and flow back into the boiler . . . down the equalizer pipe . . . and only "dry" steam to make the upward turn and travel up into the main piping.   With your piping, the only way that water is going to get back into the boiler is by flowing backward against the flow of steam.  It would have to get pretty deep in the header to flow up into your equalizer, and by that point the steam flow would be slamming it around, with all kinds of water hammer.

    If your installer left you the boiler manual, it will have near-boiler-piping instructions.  Have the installer pipe it correctly.  It will never, never, work properly the way it is.

    Even a small amount of oil in the water, left over from manufacturing and installation, will make it boil and surge violently.  The installer will need to "skim" the boiler to eliminate oil . . . and also insulate all the pipes in the basement.  It will save you money, and help the steam get to the radiators before it condenses into liquid and cause even more water hammer.
  • Jean-David BeyerJean-David Beyer Member Posts: 2,530
    Not a professional

    Was that installation done by a professional? I am not a professional either, but why did not the installer use both steam outlets from the boiler? Why no real header? Why did he see fit to insulate one of the pipes? Why not all of them?
  • Jamie HallJamie Hall Member Posts: 6,653
    I am sorry to say...

    that that near boiler piping really is pretty bad.  The Smith folks usually put out a pretty good installation manual, detailing how the near boiler piping should be done (among other things).  It won't look much like what you have...  you should get hold of it, and have your installer repipe the boiler to conform (as a minimum).

    Just a few things noted -- Smith kindly provided two riser locations.  They meant both of them to be used.  I am quite sure they said something about 24" minimum from the water line to the header, and more is better.  The header goes up before the equalizer connects; I have to admit I've never seen that arrangement before.  There are more problems...

    From the water/oil spurting out of the vents, I'm also going to bet that the boiler wasn't properly skimmed, and that it is very likely that the pressure is too high.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • TomMTomM Posts: 233
    install manual

    install manual here:


    scroll to the bottom of the page for Series 8
    beautiful Conshohocken PA
  • Big-AlBig-Al Member Posts: 263
    edited November 2010

    I attached a couple of pages from the manual that show the proper piping.  If the boiler has 3-5 sections, then using only one riser (pipe) out of the top of the boiler is OK, but if it is a 6 section boiler, then both tappings must be used . . . and from the pictures, yours looks like a 6-section.

    Show these pages to the installer and demand a proper re-pipe . . . or a refund. 
  • BobCBobC Member Posts: 4,408
    Terrible near boiler piping

    That boiler will never perform to spec until it's piped like the diagrams below.

    Note that you should always use both steam outlets if the boiler has them. Otherwise you can pull water up into the header and mains and that causes the problems you are now seeing. I don't like the way Smith has the equalizer elbowed off horizontally, but anything would be better than what you have now.

    Download, print and read the installation manual from TomM's message. Then ask the installer why he didn't follow the manufacturers piping requirement.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • CloverClover Member Posts: 1
    Is it safe to use the heat?

    It is now 40 degrees up here, is it safe for me to turn on the heat?  I am still waiting for the installer to get back to me.

    I just don't want this to blow up on me and I have towels under all of my radiators, because of all of the water/oil spurting out when the heat is on.

    Also, Thank You all so much for the information you provided. I greatly appreciate your time to address my issue.
  • Jamie HallJamie Hall Member Posts: 6,653
    Oh it's safe enough...

    make sure that the automatic water feeder is working (and check the water level!) -- you may be losing an inordinate amount of water.  But other than that it's safe enough.  Just working very poorly and costing you a bundle of cash (and giving steam heat a bad rap!).

    How's the pressure?  The further you can turn it down, the less the problems will be -- but with that boiler piping, you're not going to get rid of them.  I see a pressuretrol there; try setting the cutin to 0.5 and the differential to 1 (the differential is inside the cover).

    One thing I didn't mention in my first post on this thread -- check all the piping, particularly return piping, for height in relation to the boiler water level.  Those little Smiths (a good boiler) are kind of short, and the new water level may be lower than the original.  Depending on how the rest of the system is piped, this can cause problems...

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
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