Originally Posted by goldbryant
A certain kind of detergent would cause the arms not to rotate? The water squirts through, but not with enough force to cause them to move. Are you saying some detergents will foam and block that force?
We have town water, so adjusted to normal hardness. We don't use rinse agent. We have never needed it.
Yes, some detergents can "foam" and cause a pressure loss through the pump impeller and system. There are several conditions that can cause this. old detergent, liquid detergents separate in the bottle, the chemical compounds are combined to operate under an "average" condition, and there are more.
Like you, we never use rinse agent either, and have always used a powderred plain detergent. We've never had a washability problem.
You may want to run a dishwasher cleaning product like Glisten, or distilled white vinegar, through the dishwasher, and start over again.