The answer to when to service a dehumidifier is that you should service it at least once a year, or more often if you notice it's not working as effectively. Regular maintenance is important to keep your dehumidifier running efficiently and prevent any issues.
Start by unplugging the unit and removing the water tank. Clean the tank, filter, and any other removable components according to the manufacturer's instructions. Wipe down the interior and exterior of the dehumidifier to remove dust and debris. Check the coils and clean them if necessary. Finally, replace the air filter if it's dirty or clogged.