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  1. #1
    Join Date
    Feb 2012
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    Weil McLain CG-4 boiler roll out switch blowing

    I have a Weil McLain CG-4-SPDN boiler. It's been working great, up until today.

    The standing pilot was on, but the boiler would not fire. Both zones were calling for heat. The transformer relay was buzzing loudly.

    I jumpered the roll-out/spill-over switch, and the boiler fired.

    I went and bought a new switch, installed it, and the unit worked for 15 minutes - the switch blew again.

    I have confirmed that the electric damper is open. I have confirmed that the chimney flue is drawing (although the duct to the flue is black).

    Any ideas as to what's going on? I realize that the flame is too high...

    I have a boiler tech coming out tomorrow, was hoping to have some more insight before he gets here.

    Thanks in advance,


  2. #2
    Join Date
    Sep 2008
    Western PA
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    Do not jumper safety switches. They are there to save you life and home.

    You are beyond DIY repairs and need a competent ad qualified service tech.

    Try the link in my signature if you need to find one.

  3. #3
    Join Date
    Mar 2005
    leland nc
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    cg-4 with black smoke pipe is not a good thing
    make sure you ask him to bring a soot vacume with him just in case
    sounds like your unit sooted up from improper combustion and gas soot is the worse soot you can deal with

    make sure he has plenty of drop clothes also
    also when done aks for a combustion test to make sure it is burning and drafting properly because it isnt IMO

  4. #4
    Join Date
    Dec 2006
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    I had a boiler on friday so sooted up and it didnt have a roll out in it. The HX was full and cracked . The flue was BLACK and still clear .

    You should definitely get involved in your HVAC Co. maint program. This will keep your boiler safe and clean. You can avoid costly repairs and possibly a cracked HX.

    Your boiler would be efficiant and have a long life with this yearly routine.
    If your not getting the results you desire then change. People change from either desperation or inspiration.

  5. #5
    Join Date
    Aug 2011
    Lewes, DE
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    make sure he performs a combustion analysis on your system once hes completed..if he doesn't, you could be in the same boat again shortly

  6. #6
    Join Date
    Jul 2009
    Columbia, MD
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    sounds like an underfired boiler with a curtain effect in the draft diverter. you should have a certified combustion guy come check out your boiler

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