The low-pressure alert will activate if there is insufficient air contained within the air cells. This may be due to air leaking from the mattress or possibly due to a defective pump failing to produce sufficient air. Power failure due to the pump being unplugged, a blown fuse or a general external power cut can all cause low pressure. The most common reasons are simply user error; such as forgetting to close the CPR valve or failing to connect the tube set connector to the pump correctly. For more information please refer to instructions for use.