Jebao DCW series Pumps - controllable 24V quiet water pump features a detachable controller with mount, high quality ceramic shaft with propeller bearing to reduce wear and tear and the latest variable speed flow technology for refined control, enhanced performance, energy-efficiency and safer operations. Adjustable water flow rate: 30% to 100% of the top speed. There are 3 buttons on it, 'down', "up", "pause". When press the pause button, default stop time is 10 minutes, to cancel it please press the "pause" button again. To lock your setting, long press the "pause" button for 3 seconds, after the LED flickering for 3 times, it's successfully locked. To cancel it please do the same operation again. The controller has memory function for the flow rater, if the power goes out the controller will go back to the last setting. Error codes & solutions: Er01: abnormal working current, please check line to the pump or the controller for short circuit. Er02: controller overheat, please place the controller in a cool place, avoid exposure or high temperature. Er03: pump running dry, please check if the water line is too low to fully submerge the water intake. Er04: propeller get stuck, please check whether there are stuffs blocked the propeller or wiring errors. Er05: abnormal input voltage, please check the power voltage is 100-240V 50/60HZ.