Yes. To enable via the app, select the Radiator Settings icon and select the Open Window Detection button.
To enable via the control panel, press (power) to put the heater in standby mode and hold down (+) for 10 seconds to enter the settings menu.
Press (check mark) button to switch functions to Open Window Detection. Press (+) or (-) to select the preferred option for the open window detection. The available options are oF, 60 minutes, and 90 minutes. The default option is oF.
When enabled, if the heater detects a sudden drop in temperature (2°C or more within 5 minutes), the (open window) icon will appear and the heater will switch to Anti-Freeze Mode (fixed at 7 °C) for 60/90 minutes to prevent energy wastage as heat escapes through the window.
After 60/90 minutes have passed, the heater will return to the previous program. If the temperature drops by 2 °C within 5 minutes again, the heater will switch back to Anti-Freeze Mode for an additional 60/90 minutes.
https://www.electricradiatorsdirect.co.uk/manuals/reina/Reina-Nika-Manual.pdf