Kenmore front loading washer was giving SUDS followed by F-35. I went through a couple of level switches with no lasting success. Called in a repairman who found the new level switch I put in was bad from the factory. He made a comment that a bad flow switch can also cause these error indications. He replaced the bad level switch and the washer worked, then worked sporadically, and then got worse. I noted that the errors were coming in before the soap had time to mix with the water which suggested a failing flow switch. I replaced the flow switch about 6 weeks ago. No problems since. Replacement is easy - switch is right at top on left side under lid on my machine. A 5 minute job. Looking at the type of construction for the flow switch indicates to me that it is not a particularly long lived component.