Valid zones

Valid zones are made up of a defined set of devices, based upon what they are controlling or monitoring within the zone being configured. When you add devices to a zone and confirm by tapping on the [ Add to zone ] button, the system will validate the zone for you and will present either a tick or warning icon within the zone presented to you on your configuration screen. The tick confirms that the zone you have created is a valid one and you may now proceed to either add another zone or complete the configuration process and proceed to your live screen.

If a zone displays the warning icon, it means that the zone you have created is invalid and that if you proceed to your live screen, the devices in that zone will not be controlled by your new Cosy system. You will be required to tap on the [ Add/remove devices ] button to return to the list of devices you have selected, in order to make changes to the selection before saving these changes and having the zone checked again to confirm if valid or not.

Creating a Hot water zone without heating

In-line Switches are dual purpose devices which can either control heating or hot water. By default, they are set to heating. So as per Configuration 5 in the table below, you can have an In-line Switch on it's own, controlling your hot water. However, the configuration screen that lists all zones and groups will display this configuration as invalid due to your Cosy system expecting there to be a temperature Sensor also associated to a heating zone. To resolve this, you will need to change the device role from heating to hot water.

Simply tap on the more options [3 dots] icon that appears top right of the zone on your configuration screen. Select [Advanced settings] from the options and now you can change the device role from a heating source to controlling hot water. Your configuration screen will then show the zone as being valid and you can then continue with adding more zones or proceeding through to your live screen.

What is a valid zone?

The following table outlines what makes a valid zone for your Cosy system.


  • How can I tell if a zone is valid or not when I've added devices via the configuration screens? - If you look at your configuration screen, you should see a tick icon in the top left corner of the zone next to the name of the zone. If the zone is not valid, you will see a warning icon. 
  • How many In-line Switches can I add to a zone? - Every zone is limited to a maximum of 12 devices, made up of any combination of devices to create a valid zone. So for example, If you had a zone configured with a Cosy display, sensor and heating switch (as in Configuration 1 above), you could add a further 9 heating switches to that zone and it still be a valid configuration.
  • Can I group two zones together, even if they each have a sensor in them? - Yes. That's still valid. Zones are independent of each other, even if they share the same schedule when grouped together.