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Skim port clogged

BobbyC Member Posts: 96
<span style="font-size:12pt">Was trying to skim my boiler before the season and I think the skim port might be clogged.  I open the port and fill the boiler hoping to see water drain out but nothing.  I know I filled high enuf cause started to feel hot water in near boiler piping.  Actually the skim port piping is hot about ½ way down and then cold so maybe something is blocking it at that point. </span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">Any suggestions?</span>


  • Rod
    Rod Posts: 2,067
    Skim Port

    Hi- First of all I wouldn't heat any water till you have the skim port flowing. If there is some type of blockage you sure don't want it coming loose and spraying hot water all over you.

    Since the port designated for skimming is normally fairly large it is rather unusual for them to clog up.

    Can you show us a picture of your skim port setup and tell us what make and model the boiler is? That might give us a better idea of what might be happening.

    - Rod
  • BobbyC
    BobbyC Member Posts: 96
    Fixed it.

    Skim port is an unusual set up (i think).  Will take pic tonight and post.   Larger pipe coming out of skim port then a 90 to a smaller one then it reduces down to another smaller one with a shut off valve at the end.  Unscrewed the shut off and it was full of gunk.  cleaned it out with a coat hanger and stuck the hanger up the skim pipe set up and it was more of the same.  once all the gunk was gone filled the boiler and water started coming out the skim port.  let the water drain to right below skim port and then turned the water on real low and skimmed it for about 2-3 hours.

    Still get a "little" surging in the sight glass when it's making steam but not bad.  also water still gets a little brownish when its making steam but seems to clear when it's not running.
  • BobbyC
    BobbyC Member Posts: 96
    my biggest fear

    is when i filled up the boiler to skim the first time and realized nothing was coming out of the skim port did all that same gunk get into my pressuretrol pigtail.   Would you recommend a preventetive cleaning of the pigtail just in case?
  • BobbyC
    BobbyC Member Posts: 96
    Pics of Skim Port

    Here are the pics Rod
  • Dave in QCA
    Dave in QCA Member Posts: 1,785
    Good Idea

    It would certainly be a good idea to make sure that it is clean.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
  • Steve_210
    Steve_210 Member Posts: 646
    Brass pigtail

    If the pigtail is black you should replace it with brass
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    I'd replace both valves

    I'll bet you a case of beer that your drain pipe is full of gunk too. The trouble with those valves is that they have a tiny hole, about 1/4"-3/8", perpendicular to the direction of flow in the pipe. So in your skim port you're going from 1 1/2" to about 3/8"!

    You should replace both valves with full-port ball valves. You can attach a street elbow to the ball valve if you want to divert the flow downwards.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
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