A: First, check the controller to make sure that is working properly. Some clocks have a battery back up, so it may appear that the controller is on. If a controller is working on battery back up it will not activate the system. Plug a hair dryer or similar appliance to check the power to the outlet. Also, if it has rained recently, check the Rain Sensor override. A second thing to check is to make sure the water supply to the irrigation system has not been shut down at any point. Check the main shut off valve in the basement and at the back flow point there is usually a valve or two that can be closed and stop water flow to the irrigation lines. If everything checks out fine, call our office and schedule a service call.