My LG dehumidifier (LHD459EL) has been getting increasing loud. It shakes and vibrates enough to make it uncomfortable to be in the room when it is operating. Any troubleshooting ideas?

Well, the compressor and the fan are the only moving parts. If the fan wobbles alot, that would do it. I have also seen compressors which vibrate so much that they cause vibration issues. (very rare) Well, the compressor and the fan are the only moving parts. If the fan wobbles alot, that would do it. I have also seen compressors which vibrate so much that they cause vibration issues. (very rare)

That may end up being one of those catch 22 situations, because the case may be making the noise, but without the case off, you can't see what is making it vibrate. The fan blade can be physically prevented from turning, then the unit run again with the case back on, without harming the dehumidifier, if you don't do that for an extended period of time. Also, look at the tubes leading to and from the compressor, to see if they are transmitting vibrations if they are touching something (like the case) which could cause the noise. A little bend in a tube or some added foam in a stratigic location may solve your problem. (note: the fan blade may wobble a bit, but not be enough to cause the vibration) That may end up being one of those catch 22 situations, because the case may be making the noise, but without the case off, you can't see what is making it vibrate. The fan blade can be physically prevented from turning, then the unit run again with the case back on, without harming the dehumidifier, if you don't do that for an extended period of time. Also, look at the tubes leading to and from the compressor, to see if they are transmitting vibrations if they are touching something (like the case) which could cause the noise. A little bend in a tube or some added foam in a stratigic location may solve your problem. (note: the fan blade may wobble a bit, but not be enough to cause the vibration)