The POWERbreathe K-Series device introduces a gradual increase of load for the first 5 breaths of the training session. Once you have reached breath 5 the load is set at its maximum target-training load, and therefore becomes more difficult to overcome. The valve will not activate until you have overcome the maximum training load set by the device. Consequently if the maximum training load set is to great for you to overcome it may seem that the device is not functioning correctly. We recommend: If you are operating in an automatic mode set the intensity level to a lower level. Alternatively change to manual mode and set the load manually starting with a low load and increase the load by 5 cmH20 until you have a training load that you can complete a complete session (30 breaths) with some difficulty.