Don Vandervort, Head Homeboy, has written more than 30 DIY home improvement books, been a segment host on HGTV, served as MSN.com's home improvement expert and written countless magazine articles.
If your dehumidifier seems incompetent, it may be undersized for the space. Check the unit’s specifications to be sure it can handle the room size. If you don’t want to replace it with a larger one, try closing doors and dehumidifying your space a section at a time. After disconnecting the power cord, you can also:
1) Remove the cover and clean the condenser and evaporator coils.
2) Lubricate the fan motor bearings with a couple of drops of oil if the motor has oil ports (some dehumidifiers don’t need to be oiled). While you’re at it, make sure that the condenser isn’t clogged with dust or dirt.
3) Finally, make sure your humidistat is functioning properly by testing it with a volt-ohm meter. Just set the meter to RX1 scale and attach its leads to the humidistat’s terminals. Rotate the humidistat’s knob as far as it will turn in both directions. If the volt-ohm meter registers 0 ohms through only part of the humidistat dial’s range, the humidistat is working. If it registers 0 through the entire range, it’s broken and must be replaced.
4) If it still operates poorly, call an appliance repairperson for advice or take the unit into an appliance repair shop.
