Here are main alarms of oxygen concentrators:

Power failure alarm: In case of a loss of mains power or when the power cord is not plugged into the wall outlet, an audible alarm is activated with red indicator on.

Low- & high-pressure alarm: There is a pressure sensor on the main board to check the system pressure, when the pressure is lower than 0.1Mpa, there is an audible alarm with yellow indicator on and the oxygen concentrator is still working; When the pressure is higher than 0.23Mpa, there is an audible alarm with red indicator on and the oxygen concentrator is stopped.

Low oxygen concentration alarm (OCSI): The oxygen concentration will rise to the normal level in five minutes of operation. When oxygen purity is≥85%, the green

Lamp is on, when oxygen purity is <85%, red lamp is on for audible alarm, indicating low purity. Refer to the troubleshooting. Or call your supplier to service the device

Temperature alarm: There is a temperature sensor on the main board to check the internal temperature, when the temperature is higher than 50°C in the oxygen concentrator, there is an audible alarm with red indicator on and the oxygen concentrator will be stopped.

The troubleshooting is referred to.