Not sure how long you have had this unit. The most obvious reason could be the heating element has failed.
After going over the problems described in horror stories by owners of this model of dishwasher, I am not sure if you will be able to get LG to service it at all.
Worth asking your local LG service centre if there is one.
You should check for that the pump motor turn freely. You will have to remove the sump cover in the bottom of the dishwasher and manually turn the pump impeller. (note: screw holding the impeller on the motor shaft is a left hand thread) There may be an object there or at the cutting blade a bit lower down that is preventing the motor from turning. Motor should turn easily, smoothly, and quietly. There have been issues with magnets in the motor windings cracking, resulting in hard to turn or noisy motors. Also, models produced with serial numbers 501KW_____ to 702KW_____ may have wiring which has become embedded in the door insulation material, softening the wiring insulation, and causing a short to the motor. The fix for that is to replace the wiring harness and outer door liner with one with a different type of insulation. (not much fun to do)
You need to check to see if the drain line runs from the dishwasher pump to either a "T" on your kitchen sink drain or if it connects directly to the garbage disposal. Either connection is okay. However, water can run downhill from either connection to your dishwasher. To prevent dirty water from your sink or garbage disposal from running downhill to the dishwasher, you may have to install a dishwasher air gap. This can be purchased at a appliance parts store or a home improvement store like a Home Depot or Lowes. It is a "Y" shaped device that should be installed above the dishwasher drain line connection under the sink. As water will not run up hill, you need to make sure that the Air Gap is installed higher than the drain line's connection under the sink. "The Air Gap device should be mounted as high as you can under the sink."
I have had a similar problem on a Bosch. Don't know where it comes from, except to say the bottom door gasket appeared to be melting for some reason. I replaced it with a new one, and no signs of melting after about 3 months.
I was able to clean the black smudge from various parts of the dishwasher using Berryman's Chemtool, a carburetor cleaner available at the auto parts store. Use in a well ventilated area. Am certain naptha or other cleaner would work as well, but again, use sparingly and with plenty of ventilation. Rubbing alcohol would not cut the stuff.
one solution may be to see where drain goes into under the sink---either into the disposal or sink tailpiece. loosen clamp and pull drain out and see if it is clogged. what kind of dishwasher is it?
LE is a motor error
The Motor is working
abnormally.
Wiring connection is OK?
The Impeller of Washing Pump is
locked.
The rotor of Washing Motor is
locked.
The Blade is locked.
Check the wiring connection.
Replace the cause of restriction.
Replace the Washing Motor.
Replace the PCB.
You probably don't need to go to this guy's extremes (but he's thorough!). You probably just need the part about how to clean the strainer and bottom of the washer. I think this'll help. There are other videos, some selling products (that I haven't used). Also some of the videos are helpful, you'll just need to take a look. Once you've cleaned the goo, you can help it clean with just one cup of white vinegar and hot water occasionally. Also, use the least amount of detergent that you can, and still get your dishes clean.
You probably don't need to go to this guy's extremes (but he's thorough!). You probably just need the part about how to clean the strainer and bottom of the washer. I think this'll help. There are other videos, some selling products (that I haven't used). Also some of the videos are helpful, you'll just need to take a look.
I had the same problem. It was caused by 1 or more wires in the door that have cracked and split apart. I cut the bad sections out and reconnected the wires and it works now. The LG's are known to do this. LG said they would send all new wire harness but it would cost $200 to have a tech put it in. LG would not cover the labor.
1. No power to the dishwasher Make sure there's power getting to the dishwasher. Check for a tripped circuit breaker or a blown fuse. Check the wall socket for power. Sometimes the power cord disconnects at the dishwasher (inside the junction box, behind the bottom kick panel), if this is the case, the wiring must be repaired or replaced.
2. Door switch Replace if defective.
3. Timer Replace if defective (note: uncommon problem).
4. Selector switch Replace if defective (note: uncommon problem).
Have had a problem with our LG 5811 Dishwasher not operating.
I have found the Vent Hole Cover located inside the Door was not installed correctly. I used plumber putty between the plastic fitting and the inside face of the Door and turned the Cover fully to lock in place (vent hole is toward Door bottom). Water was leaking previously from this opening over the wires in the door.
Another problem was the lower Door Seal (under the Door) it was not installed correctly either. It was actually too long and would not seal against the bottom of the inclosure. Water was coming out and spraying the wires in the door. I had to remove the metal stiffener over the front of the Dishwasher to get to the Door Seal. I removed one end and reinstalled the seal. The Seal laid flat but was approximately 3/16" to long. I cut off the end with a sharp knife - seems to be the correct length now.
Withe the model and serial number it appears that this dishwasher is less than 2 years old.
Your symptoms point to a failed heating element. That is kind of surprising because this dishwasher ~should~ report an error code if the thermistor does not detect the raising temperature from the heating element.
The LG LDS and LDF models do NOT turn on the heating element in the drying cycle. It turns it on during the final rinse and the dishes dry as the built in fan runs.
So, I suspect the drying fan and related gear is inside the door panel. Do a load of dishes and listen for the final rinse to drain. Then, listen really closely near the top of the door for the quiet sound of a fan _and_ place your hand underneath the left hand side of the closed door for warm air blowing straight down.
If you do not hear./feel what I discribed , the drying system has failed. OH, and if you have any water leaking from the door (right where the warm air is supposed to come out, contact LG service folks and firmly request that they replace the drying parts with a retrofit kit.
Please review this and tell me what works and what questions you still have.
Good Luck and please keep me posted! OK?