Question
Jim

I have an IRRITROL RD 900 EXT controller that is not working in manual or semi-auto modes and works but causes each solenoid to chatter in automatic mode.  The output from the transformer is 24v ac.  When I press the manual button to turn on a zone I hear the first solenoid click but it does not engage.  The LCD display flutters and then after a few seconds goes back to a blinking time of day display.  I have to press the + button to set the time of day.  The same thing happens  in the semi-auto mode.  In order to sequence through all irrigation zones I have to set the start time for the zones and wait for the actual time to match.  The watering commences  and runs for the correct duration but each zones solenoid chatters during its active time.  What is a probable cause of this problem?

Answer
Hey Peter, you need to replace the controller panel. If you look in the back of the controller, you will see a ribbon of wire that is plugged into the back of the controller. You can unplug this pigtail, and the panel will come out by pulling the panel straight out from the plastic hinges. You can buy just the panel instead of the whole controller. You might also check to see if you have a fresh 9 volt battery installed. This will be a compartment at the top of the controller panel. Sometimes if the battery is weak, it will throw off the controller. What you are describing, sounds like you need a new panel. Good luck and have a great day.