Many dishwashers use at least one spray arm in order to effectively clean your dishes. While the spray arm seems like it is a moving part, really it isn’t much different from a hose. It doesn’t use a motor to rotate, but rather rotates using the pressure of the water. Due to this, spray arms actually don’t malfunction that much in a dishwasher. However, if your dishes aren’t getting clean, but the appliance is running, then it is a clear sign that this piece has started to have problems. What is happening to it?
The most common issue with a spray arm is that it gets clogged up with debris or mineral build up that comes in through the water line. Over time, enough of the holes get clogged up that the spray arm will no longer spin. Luckily, this is an easy fix. All you need to do is remove the spray arm and soak it or scrub it to remove the blockage.
Low Water Pressure
As we mentioned, the spray arm requires water pressure in order to spin. If it gets water with low pressure, it will still come out of the spray arm, but it will not rotate it properly. Usually, a low water pressure issue is an issue with the home and not with the appliance, but you may want to inspect the water inlet just in case. This issue can also be caused by blockages in the tubing leading to the spray arm, but this is often more difficult to check without some disassembly.
The water for the spray arm can come from the water in the bottom of the tub. As such, it goes through the filter first. However, if the filter is blocked, it may not get the water it needs to spin.