We ask that you hold the filter button down for 10-15 seconds to rest the filtration setting. This should solve your issue. If not , please follow steps below:
Check if you can feel any suction around the filter and filter housing unit and the water is flowing freely.
Clean the filter cartridge and the filter housing unit thoroughly as this should be clear of all filth (hair, fur, dead skin...).
After cleaning leave the filter out for 2 minutes and then reset the heater unit by pressing the filter button down for 10 seconds.
Ensure the water is between the minimum and maximum levels.