Gefran controllers: The top display is showing Hi or Lo. What does this mean?

This is usually an indication that the sensor signal is out of the configured range. Check that the input range is within tolerance:

1. Press and hold the button until is displayed;
2. Press twice - is displayed; using configure to a value in the table below:
   
3. Still in the menu, press repeatedly until appears - configure this value to minimum input scale limit using ;
4. Press once.  appears - configure this value to minimum input scale limit using ;
5. Press and hold until main screen appears.
6. Press once. appears - configure this value to minimum input scale limit using ;

For example:
If the input temperature sensor (eg TC J) is measuring 100°C, but = 50°C, the maximum range has been exceeded resulting in an error (Sbr).