You may be alerted to unexpected flow, or notice a flow reading despite a valve not running an irrigation.
The Lumo Ops Center will send an alert if;
A scheduled irrigation ends and the valve is still measuring flow
The valve does not report that it closed after an irrigation
You may also notice Unexpected Flow in Flow Vision.
Technical Overview
Diaphragm valves require differential pressure to open and close. When closing, the valve’s electronically controlled diverter directly connects the upper chamber of the valve to the inlet pressure. The inlet pressure, with the help of the spring, pushes the diaphragm down, sealing it against the valve body to stop the flow of water out of the valve outlet.
A valve may fail to close for the following reasons:
Pressure
Blocked diaphragm
Damaged/disconnected connector tubes
Failed actuator
Schematics
CLOSED POSITION OPEN POSITION
Pressure
To close properly, the inlet pressure must be greater than the outlet pressure. A may fail to close if:
The outlet pressure is greater than the inlet pressure
There is no pressure in the line
A vacuum has formed in the line (typically due to changes in air pressure in the line when water has drained. This is more common on hillsides when the Lumo valve is positioned at a higher elevation than the plant block, especially when there is no air vent to break the vacuum)
Troubleshooting Tip: Increase inlet pressure to close the valve, if possible. If the valve does not close on its own, cycle Manual Mode open and closed.
Blocked Diaphragm
The diaphragm must fully seal against the lower chamber of the valve in order to completely stop the flow of water
Debris inside the valve may prevent the diaphragm from sealing properly
Troubleshooting Tip: Attempt to clear debris from the wetware. If the valve is still registering Unexpected Flow, contact Lumo Support.
Damaged/Disconnected Connector Tubes
The black connector tubes on the exterior of the valve connect the diverter to the upper and lower chambers of the valve
If these tubes are damaged (e.g. by animals or tractor blight) or disconnected, pressure will not be properly diverted to open or close the valve
Troubleshooting Tip: Replace connector tube, if damaged. If disconnected, reconnect the tube using the black retaining nuts to secure them in place.
Failed Actuator
Water is diverted using an electric motor housed within the green dome. If the motor fails, the valve will not close.
Troubleshooting Tip: Test the actuator
If an irrigation is scheduled to run, cancel it.
Open the valve in Manual Mode
Listen for a click to come from the dome
If you do not hear a click, there may be an issue with the actuator. Replace the dome or contact Lumo Support.
If you do hear a click but still no water is flowing, replace the dome or contact Lumo Support
Note: A low battery will not cause a close failure. The valve will automatically close when the battery level falls to 29% or below.