Our dishwasher has slowly been dying on us... The dishes don't get all the way clean and there is a lot of debris and soap left on the dishes, especially on the top rack. After watching it with the door open, the middle and top arms don't spin.

We've tried cleaning out the arms- even replacing them. They spin freely when I manually spin them. Water does come out of the holes, just not with enough pressure to spin them. Bottom arm spins fine.

Float switch moves freely and isn't stuck up. Water is hot enough too. However, it seems like there isn't enough water during the wash cycle. From what I understand- the water level should be 1/2" below the heating element. When I checked our dishwasher, the water barely reached along the bottom to where the heating elements are, let alone filling enough to reach 1/2" below them. (I hope that made sense- hard to describe on computer :) ) I tried pouring a gallon of water into the bottom to see if that made a difference, but no change.

If it matters, the dishwasher drains fine and the filters on the bottom are clear.

It seems like the next thing to check would be the inlet valve, but if adding more water didn't cause the arms to spin, is it even possible for that to be the problem? What would be the next thing to check?

As much as I just adore handwashing dishes after they went through the dishwasher, I suppose it's possible that there are better things to do with my time :p

When you have the sump filter out (item 508 in section 02) of the parts breakdown, reach in and feel the chopper to make sure that it is clear of debris. Sometimes twist ties etc. can get wrapped around it.

It is a good idea to flip the breaker off when doing this just to be extra safe.

You did not say how close you got to the heater when you added the gallon of water. Perhaps add 2 gallons. On most units the water level is just below the heater.