IRRITROL RD 900 SEMI-AUTO AND MANUAL MODE PROBLEM
I have a many-year old Irritrol RD-900. I have 9 zones. If I set the automatic timer correctly everything seems to work just fine. However if I try to use the Semi-Auto Start A-B-C the unit apparetnly shorts out and the read-out screen flashes and I have to re-program the entire unit. In fact if I try to make any changes such as run a zone or run a program the screen flashes. If I set a program and let it cycle everything seems to work. If I make any changes at all the screen flashes and I have to re-program