The answer to 'why is my dehumidifier not cooling' is that there are a few common causes, including a problem with the compressor, a refrigerant leak, or a clogged air filter. A dehumidifier works by using a compressor to cool air and remove moisture, so if the compressor is not functioning properly, the dehumidifier will not be able to cool the air effectively.
Other potential issues could be a refrigerant leak, which would prevent the dehumidifier from being able to cool the air, or a clogged air filter, which can restrict airflow and reduce the dehumidifier's cooling capacity. In some cases, the dehumidifier may simply be the wrong size for the space, which can also lead to poor cooling performance.