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Weil McLain Ultra 2: DHW always on

seandarcy Member Posts: 21
I have a Weil McLain Ultra 2 for radiant and DHW. It's finally winter today, and the house didn't stay warm. When I looked at the boiler, it showed E 02 error code : "5 ignition attempts failed". I pushed the reset button twice, and it fired. But now, it's showing it's running DHW at 190F (the aquastat is set for 120F, and there's been no DHW use). And it has been for 90 minutes.

Is there some parameter that causes DHW to stay on ?


  • seandarcy
    seandarcy Member Posts: 21
    Set the aquastat to 115F. Now boiler doing space heating. I guess I need a new aquastat. Sigh.
  • lchmb
    lchmb Member Posts: 2,997
    If you had an eo2 error you need a tech to check over your system to explain the failed ignition problem. Have them check the tank at the same time..
  • seandarcy
    seandarcy Member Posts: 21
    Is it a good idea to ask for a tech to look at the failed ignition problem? I've usually thought that it's tough to check on a problem that's no longer a problem. What sort of thing should the tech be looking for ?