The i30 error code indicates that the anti-flood protection is active.
In some cases, the problem can be fixed by the tipping over of the machine and getting rid of excess water. However, this one works when the problem is occasional. Over time, things may get worse and require a closer look. The signal comes from a sensor located near the drain hole. This sensor should be protected against water and wastes by a rubber grommet. The grommet may decay over time and expose the sensor to water, so it begins to signal flooding. Also, the grommet’s fragments may have blocked the drain. In this case, the solution is pretty simple: remove the old grommet and its fragments from the system and replace it with a new one.
Also, the problem may be due to a problem in the sensor. Most likely, you will need to replace the sensor. You can either do it yourself (if you are skilled and experienced enough) or call a qualified technician.