A dehumidifier should always be properly fitted or placed in the right position for it to work efficiently. It should be able to drain excessive moist in air for you to have a good air environment. You should know how to fix it properly, ensure that it is working, there is no leakage and that it does not freeze.
Fixing your dehumidifier properly
Make sure you appliance is plugged in a working outlet and it is on. Inserting it where there is no enough power will make not to work. Make sure your power outlet is on and if it fails, unplug your dehumidifier and check if your power cords would necessary require a replacement.
Removing its cover panel
If you see any blocking ice parts, allow the ice to melt and avoid using you dehumidifier until when your room temperature is 65 degrees Fahrenheit. This will avoid your humidifier from freezing up. It does not work well in colder places and also unplugging it for a certain period without working will not solve the problem.
Testing the overflow cutoff switch
Use a volt-ohm meter to test it. Clipping the leads to terminals on the switch and depress the bar on the switch. If the meter needle fails to show continuity neither clicking back and forth, the switch is faulty. This will need a replacement for it to work.
Removing the humidistat to check
The best way you can test your dehumidifier humidistat is by using a volt-ohm meter. Set the meter to RX1scale attaching the leads to the terminals of the humidistat. Rotate the knob in both directions as far as you can. If it reads a zero ohms through the only part of the humidistat dial range, the humidistat is in good working condition. If the whole range reads zero, then it is broken and will need a replacement.
If the unit completely fails
You can take a qualified person to come and check it further. It could be the compressor motor or the overload switch that has a problem. Replacing the dehumidifier is the best solution but will depend on its value and the plan budget you have.
What you can do if your dehumidifier is still incompetent
Try to clean the condenser and evaporator after removing the cover. With a few drops of light weight oil, lubricate the fan motor bearings if it has oil ports. Not all dehumidifiers need to be oiled. Ensure that condenser is not clogged with dirt or dust.
What if your dehumidifier freezes up?
Check the room temperature if it is lower than 40 degrees. This can cause your humidifier to freeze so you set the dehumidifier on a table for it to circulate slightly warmer air. You can blow using a small blower or heater at the unit. If it solves the issue, consider to raise the temperature slightly. Be sure to set the unit far away from the walls to allow the room air to move freely through the unit.
For a dehumidifier to work properly, make sure the different parts that make up the unit are working well. Try to see if yours is working correctly and you should never assume to check it then and again. Assess it whenever it is working so that you are sure of its services to you to avoid a complete failure in the future.