WL400 Manual Page 63 – Revision: 10-23-2019FAULT CODE TROUBLESHOOTING INDEX1. Icon and Alarm on continuously – Leak Detector Sensor Alarm2. Icon ON Continuously, Alarm for 20 Seconds – the Firewall UV system is notdetecting adequate dose of UV to ensure safe water1. FAULT CODE: Icon and Alarm on continuously – Leak Detector Sensor AlarmThere are two leak detector sensors in the WL400 Water Treatment Systems.Possible Reason SolutionLeak Tray FullCheck for water in base cabinet by opening and removingfront cover.If water is found in leak tray, dry out leak tray.Unplug unit to reset fault and determine where the leak is.Leak Tray Full – with no alarmsVerify the drip tray leak clips are installed.If the drip tray leak clips are installed, the water TDS may be too low. You may need to bendthe drip tray sensor tabs inward (closer together) to improve the performance of the signalreturning to the board.`Water in Base CabinetIf no water is found in the base cabinet, open Top Cover ofWL400 Water Treatment System and remove Right SidePanel to determine where leak is.If water is found, dry out leak tray, unplug unit to reset faultand determine where the leak is.