Why are the LED lights red on my Irrigation Controller? Matt W 24 April 2020 06:44 Follow Red LED lights on an Irrigation Controller can indicate a flat 9V battery. Try replacing this to resolve indicator. Related articles Why aren't the buttons on my Irrigation Controller working? Why is my Irrigation Controller watering more than one station or zone at the same time? Why is a single station or zone not working in my irrigation system? What can I do when iGardener™ can't find my Irrigation Controller? Comments 0 comments Please sign in to leave a comment.