The answer to 'how to fix dehumidifier' is to first diagnose the issue. Common dehumidifier problems include a clogged air filter, malfunctioning compressor, or issues with the drainage system. Start by checking the air filter and cleaning or replacing it if needed. Next, inspect the compressor and ensure it is running properly. Finally, check the drainage system for any clogs or leaks.
If the issue persists after these basic troubleshooting steps, you may need to call a professional HVAC technician to further diagnose and repair the dehumidifier. Dehumidifiers contain refrigerants and electrical components that require specialized knowledge and tools to service properly.