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How to lower water level in boiler

Ed_49 Member Posts: 7
We have a WM SGO5 boilier, 1 pipe steam, 2 story house, 14 radiators. I posted yesterday asking about lowering the pressure on our boiler and received lots of input. I set cut-in to .5 and differential at 1. Seems to have definitely improved things. Less noise and better heat distribution to radiators. Still some noise but not as bad.

I also need to lower the water level. Its too high and I think this is likely to be why the system is still somewhat noisy (loud hissing). The site glass is full when the boiler is off. When operating the water level is bouncing around bottom inch or 2 of the site glass. We have a auto feeder. Not sure if it's malfunctioning or if the level has always been too high. This is a new boiler installed in early November.

To lower the water level do you attach a hose to the spigot at the very bottom, front of the boiler and open it up? I assume I should wait until the boiler is cool, turn off water supply and the boiler. There is a marking on the front of the boiler where I would lower the level to. I guess I will drain until I get there and then turn it all back on. Then I can monitor to see if the level goes too far up again which may indicate an issue with the autofeeder. Anything wrong with this approach? Any tips or other ideas? Thank you all for you help.


  • Brad White_191
    Brad White_191 Member Posts: 252
    At least Mussolini made the drains run on time...

    Hi Ed

    I think you have a number of other issues- yes the waterline can and should be lowered by draining. This is best done when the boiler is cold for safety's sake.

    Now, the fact that the waterline bounces and that it was a recent install tells me that the boiler needs to be skimmed. This is, in essence, a cleaning, but allowing floating oils (from the threading and assembly process) to be released into the water and removed from the surface in a fairly long but necessary process.

    Dan's book, "We Got Steam Heat!" and some of the materials in the library above will have more information on that process.

    If in doubt, get a professional in there.

    One feature of a good boiler installation is a skimming port, a usually large tapping above the waterline but below the boiler exit port.

    A full-size ball valve and nipple/elbow arrangement is installed to allow a "gentle overflow" of surface-borne contaminants. If you do not have that tapping, see if you can get a pro to do this. It is typically a "hot" process, the boiler being fired to below-steaming temperatures. TSP or washing soda is often used but your boiler manufacturer will be the best guidance source for your particular needs.

    There may well be other issues but I would start with a clean boiler and see how she does.

    Skimming and cleaning should be part of any install. More to it than that, but I think a good round of skimming or two will help you tremendously.
  • ed wallace
    ed wallace Member Posts: 1,613
    lowering water level

    you have the right idea of how to lower the water level you also need to turn off the auto water feed do you have all the manuals for the boiler and water feed you need to make sure the dip switches in the auto water feed match the low water cut off if its an electronic water feed the probe may need a cleaning
  • Chas_8
    Chas_8 Member Posts: 2

    Brad - as for skimming, there is a pipe coming off the front of the boiler, above water line and above the highest point of the site glass. It's about 1.5 inch (wide) and goes diagonally down. I have drained water off the top using that when the boiler was hot but off.

    I'll look into the cleaning. I spoke to the installer about that and was told they did that. That might have consisted of just filling, running and draining a little. Doubt if any additive was used.

    With our old boiler, I believe the water line bounced somewhat when running. I always thought that was just from the boiling water. Wouldn't that be normal?
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