How to Resolve the Steam Boiler Not Heating, Not Steaming or Producing No Hot Water at All on the Bezzera DUO MN

My Steam Boiler is Not Heating, Not Steaming or has No Hot Water At All

  • The display should show both temperatures for steam and brew. Make sure that your steam boiler is turned on in the menu. Make sure that your temperature is set for a range of about 250. 

  • If the display shows the machine is heating properly, check the steam tip. Remove it and make sure it is free of old milk. 

  • The steam arm is a no burn wand, and will have a Teflon tube running down the center of it. With the steam tip removed, make sure that the Teflon tube is not protruding out too far. If it is, you can push it up in to the pipe further. If the Teflon is sticking out too far, it may be partially blocking the steam tip which can result is poor steam pressure. 

  • If you are seeing an NTC Service Boiler error on the screen this is a communication error between the temperature probe and the control board. The steam boiler is the larger of the two boilers. You can remove the housing of the machine, and follow the wiring to the control board, which will be on the front left side of the machine. Remove the cover to the board, and see if any of the wiring is loose, particularly the one that leads to the temperature probe in the steam boiler. You can try removing, and reinserting the wire to ensure a tight fit.


Below you will see a close up of the terminal that plugs into the control board. It should have the 2 metal prongs visible. If one of them is loose or not present, the probe will need to be replaced. 


  • The high limit switch may be tripped and needs to be reset. Instructions for resetting the high limit switch can be found in the document attached at the end of this article.

  • The heating element may be broken and may require replacement.

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