While oxygen cylinders can run out of oxygen and need to be refilled, a concentrator will never run out of oxygen, as long as power supply for the unit is available. Principle the composition of air (78% nitrogen, 21% oxygen and 1% other gases like carbon dioxide, argon, etc.) clearly shows that air is mainly comprised of two gases: Oxygen Troubleshooting Why Would A Concentrator Stop Working The way an oxygen concentrator works is relatively simple. How long oxygen concentrator works . After air is first compressed in the concentrator, it is forced into the first sieve bed. If the oxygen concentrator is not turning on: Oxygen is sent into the product tank. Next, you will need to consider your oxygen prescription and the flow settings you will need to use. Turn the device on by pressing the power button twice. An oxygen concentrator is engineered to take in the surrounding air, compressing and purifying it by removing other agents that make breathing difficult for the pers...