LG dishwasher wont clean top rack dishes

Fill the soap cup with vinagar and run it while its empty.

You may have a stuck diverter valve inside the sump assembly. Only way to tell is to disassemble the top section of the sump assembly to see if there is any debris blocking it. You will need a technician to help you with this. Good luck

sounds like a bad circulation pump. but this is how you check. once the water start to circulate and the unit is wahing open the door and see if you have a steady water droplets at the very top evenly. if you dont 9times out of ten pump is 50 to 75 % gone and the unit is not washing properly. let me know if i was of some helpto you.

In my experience, you probably have a clog in the spray arm/arms for the top rack. Take the arm(s) out and see if the holes in them are clogged. Rice, plastic wrappers, and glass from dishes that broke in there are the most common culprits I've seen.

I had the same problem and fixed it by disassembling the lower spray arm and return filter, and cleaning all the junk out.
Most dishwashers have 'risers' that bring the water up to the top sprayer or arm located under the top rack. If the recirculating pump is plugged even a little there won't be enough volume or pressure to get the water up there.
Test this by putting a dry muffin pan in the top rack, flat, and running the dishwasher for a bit. If there is no water on the top (or the bottom) either the top sprayer or the sprayer arm underneath the top rack is not getting enough volume.
To fix this you need to clean out the screen and filter, where the water returns to be recirculated. If you don't have any confidence to remove the parts and clean it out yourself, get an appliance repair person to do the job.

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.

HI,

The top rack is not cleaning because of low water pressure from the wash motor to the upper spray arm.
Assuming the top spray arms are clear of debris, remove the lower spray arm to access the wash motor. Remove the 4 torx screws and the filter (accumulator assembly). Remove the torx screw and the inlet protector that covers the chopper assembly. Make sure the chopper is not broken (broken chopper will fill with debris and block water flow). While holding the chopper blade, reach inside the "D" shaped opening on top of the motor and spin the wheel/motor by hand in each direction to make sure either the chopper gear or the motor gear that drives the chopper is not broken. Replace the chopper if necessary . If the motor gear is broken, replace the sump and motor assembly . Remove any debris from the sump area in the process.
You don't have to shut the power off to the dishwasher because the door will be open, but if you feel more comfortable, do so.

thanks,

If you have checked everything that was mentioned (and none of them are the issue) then either the heater inside the unit is not coming on during the wash and rinse cycles and/or the fan motor inside the door is not coming on during the dry cycle. A technician can easily check this out with the correct tools and by putting the unit into test mode.

As for the top rack dishes being dirty and there being soap left in the dispenser, this sounds like wash motor is either weak or the vario motor is not switching between the upper and lower spray nozzles. The sump assembly should be replaced for this issue.

Recommend you remove the approximately 10 screws to pull the entire filter and manually clean. Remove all debris you find and thoroughly rinse out the filter if you can separate the top from the bottom. If the sump area is greasy, use a de-greasing spray to cut through it. Resemble, checking that there are no blockages in the holes on the spray arms.
Fill a bowl or cup with white vinegar and place it on the lower rack of the empty dishwasher. Do not add detergent. Run the quick cycle. The inside of the dishwasher should now be clean and not greasy. If still greasy, use the de-greasing spray (avaiable at all stores in the cleaning section.)
For 30 days, use only Electrosol or Cascade powder. Do NOT use gel or tablets, ever. Please report back your results. Good Luck!
ianc435 , please ask your question in as a new problem and I will help you out. I understand your problem.

Please confirm that you own an LG LDF7811 dishwasher and it is not cleaning properly.
-Are you getting any error codes displayed? -Did you remove the mesh filter and clean any debris beneath it plus rinse out the filter itself?
-Are you using a name brand diswashing powder? Avoid ultra-cheap detergent, especially in water-conserving units like the LG 7811. Never use DW gel or tablets in any dishwasher.
-Do not over rinse the dishes before placing them in the DW. The food granules actually are used to clean all the dishes before being rinsed away.
Please try these suggestions and reply to this message with what worked best and if the problem continues. Good Luck!