The answer to 'when to replace dehumidifier' is that most dehumidifiers have a lifespan of 8-10 years with proper maintenance. Signs it may be time to replace your dehumidifier include decreased efficiency, increased noise, and inability to maintain desired humidity levels. Replacing an older, less efficient dehumidifier can also save energy and reduce your utility costs.
Proper maintenance, such as regularly cleaning the filters and coils, can help extend the life of your dehumidifier. However, even well-maintained units eventually wear out and need to be replaced. If your dehumidifier is over 8 years old and struggling to perform, it's generally recommended to invest in a new, more energy-efficient model.