E20 displayed and unit locks out regeneration until service is performed

Safety: No immediate hazard, but follow standard precautions when servicing.

• Review service log: Check installation records for last resin replacement, valve service, and disinfection.
• Perform maintenance: Clean brine tank, check injector and screens, inspect seals and spacers, and test regeneration function.
• Reset service counter: Access the service menu and reset the maintenance interval according to Aqmos instructions.
• Update settings: If resin has been replaced or system upgraded, update capacity and service interval parameters.
• Monitor operation: After reset, verify that the unit regenerates normally and that water hardness is within specification.