Homeowner is replacing refrigerator and needed a code compliant ice maker box installed. The washing machine drain was continuously backing up when draining. Due to the old cast iron drain the solution was to replace the drain line with pvc. Cut out and removed section of cast iron. Piped in new pvc and connected to either side of the cast iron. New washing machine box was installed. Everything was tested for proper operation and found no leaks. Additionally ran both hot and cold water in the new PVC for 5 minutes without issue.