Does the dehumidifier require regular maintenance?

The dehumidifier is a solid-state unit with no compressor, so it needs no consumable service. The routine that keeps performance stable is about the cabinet as a whole: keep the door gasket clean and undamaged so the seal holds, keep the interior free of dust, and leave reasonable clearance around the cabinet for airflow. If the displayed humidity starts drifting from the setpoint under the same conditions, that is the signal to check the gasket first. Spare parts are stocked — tell us the model and we will supply the correct item.