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gehring_3 Member Posts: 74
The other day my boiler stopped running and when I investigated I found the mecury switch in the Pressuretrol has gotten hung up exactly in between cut out and cut in - i.e. it was just suspended there in an in-between state of limbo. I gave the unit a gentle tap and the mercury dropped over to the "on" position and the boiler fired up. The unit is completely level, the pigtail is properly fore and aft oriented and this has never happened before and hasn't happened since.

What would cause the switch to hang up in the middle just that one time? Luckly I was home - if I had been away I would have had a problem. Does the unit need to be cleanned periodically or lubricated or what?

Thanks in advacne for any tips.


    EBEBRATT_2 Member Posts: 5

    Could be that a small shot of WD-40 will help if it is the mechanism. I would be concerned about the possibility of dirt or sludge plugging or partially plugging the steam connection. I would suggest removeing the control and making sure the pipe connections are clear and that a "pigtail" is installed. Brass nipples and pigtail are preferable and may be required in some locations. A high limit control is a safety control and if you find nothing wrong with it--you may want to replace it for safety sake. You still have a safety valve--but better to be on the safe side.
  • gehring_3
    gehring_3 Member Posts: 74

    There already is a pigtail installed and it is oriented properly. Also, the unit is only a little over one year old so I can't imagine it has gone bad already.
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