No steam on Capresso Impressa S8

I have 2 Jura Capresso Impressa S8 coffee machines. One is set up to use water filter, the other is not. While changing the water filter, first machine wouldn't complete rinse cycle, appears to not have steam function work- it grinds away, but no steam. I finally just started using it without filter.Next machine quit during decalcify cycle- same problem no steam. Makes me believe there is something defective in design- 2 machines malfunction in same manner.Question is- how to retore steam function which probably is core problem.