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Weil-McLain EGH boiler issues.


I'm dealing with a Weil-McLain Series 2 EGH hot water boiler and there seem to be a few screwy things going on.  This boiler is vented via a power vent out the side of the building.  The power vent works alright, but it turns off a few seconds before the burner shuts down.  For the last few seconds of the firing cycle, there is no power vent.  This can't be right, can it?  For whatever it's orth, the boiler features a standing pilot, the control for which is a Honeywell.

Where the boiler exhaust is vented, there is a small vent housing with a stationary plate inside covering the flue/duct opening.  I'll try to get a picture tomorrow (it's too dark now).  My fear is that it might be too restrictive.




  • Jim Davis_3
    Jim Davis_3 Member Posts: 578

    You are absolutely correct!!  The venter should actually run for several minutes after the burner shuts off.  However most are set for 20-30 seconds and have to be modified with additional controls.  Sounds like a board problem.  This boiler could start sooting up very quickly and be very dangerous.
  • Tim McElwain
    Tim McElwain Member Posts: 4,625
    Whose Power venter is it?

    It had to be a retrofit as the EGH is not power vented.  In fact if you look it up www.weil-mclain.com  it can't be sidewall vented at all. Shut it down make it inoperative and tell them to get the installer back.

    Some versions are shown with a vent damper does yours have a damper?

  • Volvoguy87
    EGH CO issues.

    I'm working on a short contract basis at The Campbell Center for Historic Preservation Studies and my last day here is this Saturday.  The Campbell Center took over the campus when Shimer College moved out circa 1979.


    The building in question is the library.  Fortunately, there's nobody in there in the winter and the place is only heated to about 50-55 degrees.  The building was originally heated via 1-pipe steam on the campus's central boiler system.  That boiler was last fired in 1978.  The Weil-McLain EGH boiler was installed some time after that and the system was converted to pumped hot water.  The building has no chimney, so side venting is the only option.  Since this installation is about 30 years old, I doubt the installer can be located or brought back.

    I don't know whose power vent it is, I'll check once it's light.  I'll also check for a damper.  I know the boiler room once had a fresh air intake with an automatic louver, but it malfunctioned and was never repaired.  Now there is a note on the boiler room's door which instructs people to leave the door open at all times.  It looks like band-aids on top of bubblegum and spit for the last 30 years.

    I just cleaned the burner tubes and they were actually pretty clean.  The other EGH boiler in service (steam, not HW and it's also power vented out the side) has burner tubes that just dump ash / soot when they're upended.

    Sorry for the delay in response.  Some kids broke into one of the vacant buildings and pulled a 400 amp breaker which killed power all over the campus, so that took my full attention.  I doubt they had any idea the breaker was live.  I hope, had they known it was live, that they would have realized just what kind of damage 400 amps could do.  Personally, I'd rather not have to go find the charred trespassers.

    I'll look into this boiler some more,

  • Volvoguy87
    Some pics.

    1, the boiler's flue from outside.  The exhaust vent is the brown box on the left and the window well on the right has a shutter (disabled and closed) for intake.

    2. Closeup of the vent.

    3. Inside the vent.  There is no movable damper or shutter in this vent.

    4. The mighty beast.

    5. The disabled combustion air intake shutter.

    6. The exhaust flue from the boiler with the power exhauster.

    7. Closeup of the power exhauster.

    8. Last one of the power exhauster.  Lovely wiring, isn't it?  I'd nominate this for the contest, but it's hot water not steam, and there are worse systems pictured already.

    How dangerous is this thing, bad, worse, or ugly?

  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    edited November 2010
    It s a hazard for sure....

    You're not going to have time to fix it before your tour of duty ends. I'd recommend that you get the utility purveyor involved. This way, the deficiencies are legally noted, and the appropriate actions MUST take place.

    The combustion air damper MUST be interfaced into the start up sequence, and there is usually a master control box that makes all of these decisions. It receives the call for heat, and then opens dampers, and confirms its own blower has started prior to allowing the burner to engage. Upon cessation of the heat call, it snuffs the flame, and post purges the boiler and closes the damper.

    At a minimum, make certain that there is a code approved CO detector in the immediate vicinity of the mechanical room, "Just In Case".


    There was an error rendering this rich post.

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