I'm having a problem with my wwhirlpool duet steam washer. I am getting an f 21 fault, I know to check the pump filter and it's clean. I checked the drain line and it's clear also. When I turn on a cycle, the pump turns on and discharges any residual water, it goes through the whole washing cycle and the pump turns on when it needs to with no problem and discharges water, again with no problem. The problem happens when it goes into the drain and spin cycle, the pump doesn't turn on and eventually the f21 appears. When I clear the fault and restart the machine, the pump goes on and works just fine. I've run through the diagnostics and it cycles through from C00 to C08, I'm leaning towards replacing the CCU. Any ideas before I do? Thanks for any help.

Thanks sidfink43. I think I may have found the problem, about an hour ago my wife told me the washer was doing it again. I watched the washer run and I waited to see if it would happen again. It did. When I touched the pump motor, it was hot and had a very small vibration. I removed the plug and put my volt meter on it to see if there was power going to the motor. It read 120vac. When I plugged it back in the pump kicked on. I guess the motor is intermittently binding up, probably when it gets hot. That's why it would do it late in the cycle. I'll start with that, if it turns out to not be the problem, I'll order a CCU. Thank you, I appreciate the help.