And, if one wash is not long enough to heat the water, you can always turn the dial back to repeat the wash to get hotter water. Unfortunately, the older dishwashers, with the exception of the Westinghouse Roll Outs, did not have long enough wash periods for enzyme detergents to do their work. The Westinghouse Roll Outs had a thermal hold to 140F and would wash for 45 to 50 minutes to heat the load to 140F. They had no prerinse, just a warm-up spray before the wash so wash times were generally long.