Whirlpool DU1301XTV dishwasher - the top rack started cleaning woefully a few months ago. The bottom seems OK. I checked wash arm action by starting the washer and opening the door several times. The bottom wash arm spins fine, as does the one under the top rack, but the very top one on the inside 'ceiling' of the unit that runs water over the top of the top rack does NOT turn. I pulled out the tube that carries water up the back to the top two arms and checked everything. The top-most 'ceiling' spinner turns freely and I cannot discern any blockage - even so I took it apart and cleaned it anyway. I poured water in each end of the tube and it rolled freely to the other end, so there is no complete obstruction. My suspicion is that something is blocking this tube enough to reduce water pressure to the top rack, but that tube is very flat and does not open. How can I clean it out or check in there other than a wire or bent coat hanger. Also, any other ideas anyone has that I can check? Thanks!

Hi, many thanks for responding!

Shortly after writing my initial query I figured out how to inspect the feed tube. I fully removed it from the dishwasher and held a flashlight behind it so the light shone through. The plastic was white, but thin enough that could do this the full length and spot any potential blockages.

Turned out it was not blocked, but there was a lot of growth and scale everywhere, so I manually cleaned everything the best I could, then ran two HOT cycles with just Dishwasher Magic. Now it cleans almost like new again!

Seems the newer HE washers have a lot of nooks and crannies that don't get soaked, but just moist enough that they are conducive to lots of fungal growth. I think a full breakdown and scrubbing will be added to my maintenance list twice yearly for this machine! Hi, many thanks for responding! Shortly after writing my initial query I figured out how to inspect the feed tube. I fully removed it from the dishwasher and held a flashlight behind it so the light shone through. The plastic was white, but thin enough that could do this the full length and spot any potential blockages. Turned out it was not blocked, but there was a lot of growth and scale everywhere, so I manually cleaned everything the best I could, then ran two HOT cycles with just Dishwasher Magic. Now it cleans almost like new again! Seems the newer HE washers have a lot of nooks and crannies that don't get soaked, but just moist enough that they are conducive to lots of fungal growth. I think a full breakdown and scrubbing will be added to my maintenance list twice yearly for this machine!

Yes.... and add to that that many people do not use the dishwasher everyday nd you have a big problem... Yes.... and add to that that many people do not use the dishwasher everyday nd you have a big problem...