Dehumidifier: Runs all the time
If the dehumidifier runs continually and constantly collects water, it's likely that the dehumidifier's capacity is too low for the space; add another dehumidifier to the space to increase the water-collection capacity. A defective humidity sensor can also cause the dehumidifier to run constantly. If the evaporator is iced up and not defrosting, you may need to replace the evaporator thermistor-the dehumidifier won't collect water if the evaporator is iced up. If you see no frost on the evaporator while the dehumidifier is running, and the dehumidifier isn't collecting water, the dehumidifier may be low on refrigerant or the compressor may be defective. See the repairs below for ways to correct the problem.
Replace the dehumidifier evaporator thermistor
The evaporator thermistor is a temperature sensor on the evaporator coils. It communicates the temperature of the evaporator coil to the electronic control board; if the temperature is too low, the electronic control board detects excessive frost and begins the defrost cycle. If the thermistor isn't working properly, the electronic control won't defrost the coils. Replace the evaporator thermistor if it doesn't detect the evaporator temperature.
Replace the dehumidifier humidistat
The humidistat is a sensor on the front of the evaporator coil that monitors the humidity of the room air being pulled in through the evaporator. The humidistat communicates the humidity to the electronic control board through a wire harness connection. If the thermistor is defective, the electronic control won't properly detect humidity and dehumidify the room. Replace the humidistat if it doesn't sense the humidity.
If the dehumidifier doesn’t respond when you try to set it, follow these steps to replace it.
If the humidifier sensor doesn’t properly detect humidity or evaporator temperature, install a new sensor assembly, following these steps.
If the dehumidifier won’t power up because the control board has failed, use the steps in this repair guide to replace the electronic control board and fix your dehumidifier.
Why your dehumidifier doesn't collect water and how to resolve the problem.
Get help deciding what size of dehumidifier to buy.