My LG dishwasher upper rack has stopped cleaning. The uppermost arm is seemingly getting no water at all and the arm on the underside of the upper rack is getting some water, but not enough to turn it. I have already disassembled and cleaned all the way down to the diverter assembly and it has not fixed the problem. I think this is a problem with a the (?) diverter pump or perhaps a sensor that sends water to the upper arms. I am trying to figure out how to further diagnose the problems. There is no error code on the readout. Any advice??

Remove the upper wash arm from the rack. Examine thoroughly. Look for hair line cracks especially if the wash arm is plastic. Top rack wash arms have spray holes on the top AND bottom. Check both places. Sometimes small fish bones will clog the hallway of wash arm not just the holes. After years of use, the wash arm will bow especially plastic ones. Be sure the water connection to wash arm is Secure. If you think the wash arm is not spinning, try this. Place a old cell phone inside a sealed glass jar and start recording video from the lower rack. Be sure jar is Secure. The light from phone will come on. You might see the problem this way.

Check for a worn bushing washer on the lower arm. Also, make sure the arms are clean inside - they are propelled by reaction from the water jets spraying out, and clogs will prevent proper water flow through the jet orifices. Sometimes food debris will get through the pump and cause this problem. The diverter valve may also have trash inside clogging it and keeping from seating properly - this could account for both low pressure at the spray arm and water coming out of the lower rack when it should not.

Make sure the center loading is not obstructing the water jet to the top shelf. Top shelf is only for glasses and saucers , use Jet-Dry .Pre rinse and clean bottom pan strainer from dirt debris.

Hi,
When my wife started complaining about her dishwasher not getting the top rack clean this is what I found and I wrote a tip about it...

Dishwasher Spray Arms not Spinning

http://www.fixya.com/support/r4817172-dishwasher_spray_arms_not_spinning

heatman101

Check the upper arm for free spinning, then remove the arm and check that the seam between the upper and lower halves has not split somewhere. Also check all the small holes for debris plugging. Run the machine in wash cycle for a little while with the upper arm off--that should flush out anything blocking the pipe up to the arm. If still nothing from the upper arm, tear down the lower arm assembly down to the deck while noting position of all parts removed. Clean the big screen at the bottom in white vinegar and hot water. Inspect the holes in the bottom for anything blocking them.

Just to review, the LG dishwasher family, including the LDS5811 has the Verio motor and the check valve that diverts water from the bottom rack to the top rack.

If the valve is blocked/jammed, this would cause the symptom you describe. The valve is visible from inside the DW after you open it up.

It is also possible that this motor has failed.

Yes there is the Water Div valve, it diverts the water between the wash arms.

Yes, run an empty load with 1/4 cup vinegar. It sounds like there is mineral build up in the arm. Try to take the arm apart that supplies water to the top rack of the dishwasher. You can soak this in vinegar water once removed.

I had similar problem. the problem was due to having not enough water pressure in the line to the upper srapy arm. Did the following:

1. removed debris from sump assembly;
2. removed wash motor and clean clogged separation screen; and
3. sealed with Teflon tape manifold and probe manifold of the upper sray arm.

If you google for 'whirlpool 8178022' you should be able to get KD-12 repair manual.

Goof luck.

Amjad

Can you tell me if the problem was fixed by the original posters?
The multi-level wash direction feature uses a check valve just below the mesh filter asembaly and is driven by a vario motor underneath the check valve. By removing the mesh filter (10 screws and the lower spray arm) you expose the check valve. It is very close to the pump that empties the water through the drain hose.

High probability problems: -The Check Valve could be jamed/stuck. -Also, the Vario Motor could have failed
Please respond back with the findings on this problem. Thanks!