The same problem a lot of people are having with their LG dehumidifiers:

SOURCE: Dehumidifier Error?

This error code indicates that the problem is most likely a shorted defrost thermistor or possibly a pinched wire going to the thermistor. You will need to replace the sensor assembly - part # 6877A30013L. The Sears website has it listed for 9.99 + shipping. The humidity sensor & defrost thermistor come together in a wiring harness that plugs onto the main circuit board. It is fairly simple to repair. Just remove the front & rear grill & the metal cabinet. Remove the thermistor from the copper tube on the cooling lines; remove the humidity sensor from the front of the evaporator; pull the wire plug off the bucket switch; & remove the small 7 pin plug from the main circuit board inside the metal control box. Reverse procedure to install new sensor assembly.

SOURCE: LG dehumidifier

Hi,
Here is a tip that I wrote to help people with just that dehumidifier problem..

Dehumidifier Problem It shows Bucket Full
http://www.fixya.com/support/r4688381-dehumidifier_problem_shows_bucket_full

heatman101

SOURCE: My dehumidifier is a LG model LHD45ELT8. the

Hi,

Here is a tip that explains what can be happening to make the dehumidifier show that the bucket is full when it is not.

Dehumidifier Problem It shows Bucket Full

heatman101

SOURCE: My new LG "ld450eal" DeHumidifier

The switch that says 'Bucket is full' is not adjusted properly.
It will need to be adjusted, normally a screw driver or pliers,
so that when its empty the switch is not made or the contacts
are open.
If it is in adjustment properly, then the switch is bad and needs
replacing.
Before you replace it, check to make sure the wires leading to it
are not touching, it may be sending a signal meaning 'full' by
electricaly touching each other at the switch.

SOURCE: HI I have an LG-LD450EAL

Check the bucket first, it might be full of water and the unit refuses to start because otherwise the water would spill.
If after emptying the bucket you get the same CH 10 message then the sensor assembly, Part # 6877A30013M, has failed and you will need to change it - here it is
http://www.encompassparts.com/products/?6877A30013M
Easy to change, just take out the rear covers and the new part plugs into the control board - the old one is secured with a small plastic clip , crimp it to disengage it.