The Modulating Thermostat can only control the Domestic Hot Water of OpenTherm boilers equipped with a water tank.
Like for the heating, a planning can be created to turn ON or OFF your water heater depending on your needs. You can also check and modify the domestic hot water temperature from the mobile app in the parameters of your Thermostat:
Home + Control app > Settings > Manage my home > [Room of the Modulating Thermostat] > [Name of the Modulating Thermostat] > Advanced settings > Domestic Hot Water temperature
In case of a long leave, it is recommended to use the 'Away' mode. This mode will automatically turn OFF your water heater.
In summer, when you want to turn OFF your heating but enjoy hot water for your showers, apply the 'Frost-Guard' mode. Your domestic hot water planning will still be applied.