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I need some professional help

peteboy Member Posts: 18
This summer I switched out my old Thatcher oil fired steam boiler for a new Thermoflo GAS-150 steam boiler. My old oil company used a "professional" install company to do the work. I thoughtI had asked all of the correct questions and the installer even new Dan from attending some of his seminars. i thought they did a very neat, efficient job. I fired up the boiler tonight for the first time and was very pleased about how quiet the system was and how rapidly and evenly the radiators became warm. Gone was the noise of banging pipes and hissing vents. Tonight when the boiler cycled on a few hours later, we heard a noise in the basement. I thought the dog had peed on the floor. We noticed that water had leaked out from one of the main steam vents. The installer put in the 2 new main vents as we had none before. I also noticed that the water level in the sight glass was very low and then the LWCO light came on and the boiler shut itself off. Once that happened the water level rose to the normal level in the sight glass. My contract with the installer stated it would be piped to the manufactures specifications. Obviously something was done incorrectly. I am asking for any advice so that I can have the installation corrected. I have enclosed some photos of the piping.


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,573
    new install

    was the boiler skimmed?

    this involves [in my case] the simmering of some arm&hammer baking soda solution in the boiler for several hours, followed by a "skimming" of the oils left over from new piping. this procedure, can take a few hours more.

     the result would be a clean boiler, and a steady waterline, which is essential to any new installation, or major pipe-work, in order to avoid a wild waterline with too much water going out into the system.

    do a search here for that term.--nbc
  • peteboy
    peteboy Member Posts: 18
    Boiler skimming

    @nbc, I do not think it was skimmed as it was only test fired during the installation. This is the first time it has been run for awhile.I have read about skimming on this board and will do a search. Could it be that simple of a solution?? Does the piping look to be done correctly? Is this something I could do myself or should I get the install company back? I am a home owner who has done his share of repairs and have installed my own DHWH (of course I got it inspected after the install). Thank you very much for the advice.

  • peteboy
    peteboy Member Posts: 18
    skim port

    I did a search on skimming a new boiler and realize it needs to be done from a fitting or valve above the water level. I do not see a skim valve or "Tee" where it could have been installed. Any suggestions on how to proceed? It's starting to get cold outside.

    thank you

  • BobbyC
    BobbyC Member Posts: 96

    looks good here but i'm not a pro.  header is def 24 inches above water line and your 2 sep main takeoffs look good. 

    I would recommend maybe piping your main steam vents in an antler configuration to pro-long their life.  

    Regarding skim port - see that circle of yellow insulation next to your site glass that I believe would be an ideal place for your skim port.  that is where I have mine.   I have attached a pic of mine so you can see. 
  • peteboy
    peteboy Member Posts: 18
    Thank you

    Bob C and NBC, thank you for the reply. I never realized there was a plug behind that insulation. Seems like a simple fix. @ Nick, How would I add chemical now ie. baking soda? Just remove the pressure relief valve add through there? How much baking soda to add. How often should boiler be skimmed? These may sound like dumb questions but I want to do it correctly.


  • Rod
    Rod Posts: 2,067
    Boiler Tappping

    Hi-  First of all I'm a homeowner not a professional so keep that in mind :)

    I’ve attached a copy of your boiler’s I&O manual (Installation & Operating) as apparently the installer didn’t leave it with you.  Page 7 in the manual shows the different tappings on the front of the boiler and the location of the skim tapping. I would suggest you have a pro remove the plug from the skim tapping for you as these are tightened at the factory and can be a “bear” to remove. I would have them install a 10 or 12 inch pipe nipple with either a pipe cap or a full port ball valve on the outer end.  (I might note here that it you have any valves on a boiler that could  cause injury if they were accidentally opened and steam /hot hat would squirt out, you should further cap or plug the valve. This is especially important if you have inquisitive  kids or grand kids!

    Boiler pipe sizes-  Page 11 in the manual states the recommended pipe sizes of the boiler risers and header which for the GSA-150 should be 2 ½ inch pipe. (You can check this by measuring the circumference of the piping and for 2 ½ pipe the circumference should be 9.032 inches.)  The equalizer should be 1 ½ inch pipe.

    The skim instructions are given on Page 17 of the manual.  Generally the consensus is that adding chemicals to the boiler water is frowned upon and the instructions don’t mention adding chemicals.  If your boiler water is bouncing more than 3 /4 of an inch above and  3/4 of an inch below the operating water line you probably need to skim. Also an indication that you need to skim is if water droplets form on the inside of the glass sight tube above the water level.

    As for the slow return of the condensate - your returns might be a bit on the small side. At what pressure is your boiler operating ? It should be at less than 2 PSI max.  In the I&O manual in some cases there needs to be a reservoir added which might be the case with your system.  First I would do everything I could to encourage the return of condensate. Make sure all your radiators are slightly sloped towards the inlet pipe to encourage the condensate to flow back to the boiler. Also check that the non operating water level in the boiler is 23 13/16 inches above floor level. (Page 11 in the manual) If there isn’t a mark on the tube or boiler cabinet make an appropriate mark for further reference.

    - Rod
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