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skim a boiler after new install

what is the proper procedure after installing a new steam boiler.  also do you skim with chemical


  • Unknown
    edited April 2010

    Hi -Generally the consensus is to try and stay away from adding chemicals to the boiler water. Some use TSP to  clean the boiler. Rhomar Water makes some very good products. If the manufacturer's I&O Manual suggests what to use, use that.

    Skimming- You can do either a "hot skim" or a "cold skim". I cold skim as I think the oil is more likely to collect on the surface oil the boiler water when the water is cooler.

    How you hot skim - There is a good description on hot skimming on Page 20 in the June 2009 issue of Oil Heating Magazine. The head tech from Weil McLain gives a detailed instruction of how to skim / clean a boiler.

    How you cold skim - With the boiler cold (cool) open the skim port and place a 5 gal. plastic bucket under the port to catch the runoff. Open the fresh water valve supplying the boiler and slowly flood the boiler till the boiler water runs out the skim port. The water should just trickle out- the slower, the better. (What you're doing is skimming off the tiny bit of oil on the surface of the water) I fill the 5 gal bucket in about two

    hours so that should give you an idea of how slow it should be. After you have

    finished skimming close the skim port and turn on the burner till the boiler makes steam. You should ALWAYS boil the boiler water after you add fresh water to the boiler as the heating drives off dissolved oxygen which can damage your boiler. You may have to repeat skimming several times till you get a "happy", no bouncing water level. Let the boiler run a day or two between skimmings. 

    - Rod
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,448
    skimming a new boiler

    generally the mfg will have some very specific instructions as to skimming, which should be followed in order to keep the warranty intact.

    for instance Peerless recommend simmering a solution of arm&hammer washing soda in the boiler, before skimming. the presence of a large diameter skimming port makes it more effective, but it is always time-consuming.--nbc
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