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Weil McLain Ultra II stuck on DHW

seandarcy Member Posts: 21
This boiler serves for radiant and indirect DWH. The DWH aquastat is set for 120. The display on the boiler shows "4 180", all the time. I've tried Reset. I've tried powering it off and on. And, of course, this happens in the middle of a huge nor'easter !

Any help appreciated.



  • the_donut
    the_donut Member Posts: 374
    Sequence 4 is DWH. You could temporarily disable DWH priority to get radiant up and running. It may be an issue with your dwh aquastat or wiring. Pics would be helpful. Here is control manual.
  • the_donut
    the_donut Member Posts: 374
    I see you had issues with E02 and some aquastat issues. I would try disabling DWH parameter 2 by setting it to 0 and have a tech come out and hone in on the problem.