Magnetic contact sensors are generally low-maintenance devices that require little attention once they are installed. However, it is important to check them periodically to make sure they are still functioning properly. This can be done by opening and closing the doors and windows to test the sensors, or by using a magnet to simulate the opening and closing of the sensors. If any sensors are found to be faulty, they should be replaced as soon as possible to ensure the continued effectiveness of the burglar alarm system.