Have VGreen 165; about 7 years old. Motor does not respond to Stop button. Randomly stops on its own, then instantly starts again. This was an issue last year. Turning off circuit breaker; push buttons to clear any memory, and then turning it back on worked then, but not now. Looked into replacing user interface, but it seems that that is not an option for this model. Am a complete loss as how to proceed from this point. Other places and/or parts I should examine? Should I consider replacing VGreen165 motor (with what?); if I replace motor, should I replace pump, too? (it seems to be working just fine). Suggestions most welcome!! Thanks very much.