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Dishwasher Arm Below the Top Rack Is Not Spinning

While some dishwashers only have one spray arm, several models have a secondary spray arm dedicated to the top rack of dishes. Unlike the bottom rack, which is set underneath all dishes and only over the drain valve, the top spray arm must contend with the dishes beneath it. For this and several other reasons, the top rack spray arm may experience malfunction or even break down.
  1. Obstruction

    • Perhaps the easiest to fix and also one of the most common issues with the top spray arm is a physical obstruction preventing the spray arm from turning. Often, this obstruction takes the form of a mug, dish or pan that is positioned too low on the rack and physically blocks the spray arm as it turns. The spray arm is also obstructed by accumulated food particles that gum up the shaft on which the spray arm turns and clog the water jets. If the dishwasher is properly loaded and the spray arms will not rotate, remove the wash racks and clean the spray arms thoroughly, looking for particles of food that may have accumulated near the base or in the jets.

    Water Pressure

    • Another reason the cycle may not operate correctly is the water pressure. The spray arms rotate on the force of the water pumped into their system. If only a little water is available, the pressure necessary for both arms may not accumulate. Ensure the float assembly is moving up and down correctly and not encumbered by debris. If the float appears functional, ensure the drain valve is not open during the initial fill of the dishwasher.

    Broken Arm

    • Of course, a spray arm that is warped or broken by repeated impact or manufacturer’s error will not operate effectively. Examine the arm for cracks or bends that may prevent it from working correctly. A broken or warped arm is not repairable and must be replaced with a new component. Contact a service technician for replacement options.

    Pump and Motor Assembly

    • While water may set the spray arms spinning, the pump and motor assembly channel the water from the bottom of the dishwasher up through the spray arms. A fault in this apparatus will cause one or both of the spray arms to stop working. Unlike simple obstructions on the spray arms, the pump and motor assembly is a complex part of the dishwasher and a service technician is required for any repairs.