Make sure the foot control is correctly positioned in front of the device and nothing/no one is positioned between the device and the foot control.
Make sure you are using lithium batteries.
Alternatively, you might need to re-pair the foot control with the unit.
Perform a new pairing by watching the video on the maintenance chapter. Go to MAINTENANCE section and select How to pair the wireless pedal with the AIRFLOW® Prophylaxis Master & AIRFLOW® ONE?
If still not solved, contact EMS aftersales service."