There is a “No Entry” symbol and a solid black square on the screen of my NCU2T Nobo heater controls. What is this?

If a “No Entry” symbol and solid black square appear on screen, the NCU2T has developed a fault and will need to be replaced. It will stop the heater from running and no setting change can be made. A replacement NCU2T or NCU2Te may be required.

Note; if there is a “No Entry” sign, but no black square in the corner of the screen, then it is likely the cassette is in Setback mode and the temperature has been turned right down to the OFF state. Double check if there is a SUN or MOON in the top corner, or if there is a Black Square.  Only the “No Entry & Black square” together indicate a fault.