Please update the firmware to version 3.2.1 then follow the steps.
1. If you see a "#900 Cooler Off" dialog appears on the touchscreen, press "Continue". If the error message did not pop up again within one minute, the machine should operate normally.
2. Check if the water level of the cooling tank is at least 8/10 full.
3. Please check whether the water pump is working. Go to the machine interface>MAINTAIN>press "PUMP" and make sure whether the water pump is working with the blue light on.
4. Please check whether the water tube is folded anywhere, especially the part in the following picture.
5. Please check the flow speed following the steps below: Screen panel > Machine > Hardware settings > Test flow speed.
6. If the error message pops up again, please refer to Water Cooler Maintenance, change the water and try again.
7. If the solution didn’t work, contact FLUX Support.