E19 displayed and thermostat indicates geofencing or presence detection error.

Safety first: No electrical hazards are involved; this is a software/service issue.

• Step 1 – Check app permissions: On your smartphone, ensure the Atlantic app has Location permission set to Always or While Using, as required for geofencing.
• Step 2 – Update app: Install the latest version of the Atlantic app from your app store.
• Step 3 – Re‑enable geofencing: In the app, disable geofencing/presence detection, save, then re‑enable and follow the setup wizard.
• Step 4 – Account check: Ensure you are logged into the same Atlantic account on all devices and that the thermostat is correctly assigned to your home/location.
• Step 5 – Wait for sync: It may take several minutes for the thermostat and cloud to resynchronize presence data and clear E19.