E20 error and the unit indicates an external leak or tray sensor activation (on cabinet models with base sensor)

Safety first: Disconnect power and close the inlet valve immediately. Avoid standing in water near electrical outlets.

• Remove front cover: Access the base of the cabinet and locate the leak sensor or pad. Mop up any standing water and dry the area thoroughly.
• Trace leak source: Check the brine line fittings, the base of the brine tank, and the underside of the valve for signs of fresh water or salt deposits.
• Test brine tank: Fill the brine tank partially and watch for seepage from seams or around the brine well. Replace the tank if cracked.
• Check valve O-rings: Inspect the connection between the valve and resin vessel for weeping. Replace O-rings if necessary.
• Reset sensor: Once the leak is fixed and the base is dry, reset the leak alarm according to the Monarch manual and restore water and power.