What You Need to Know Before You Buy

How does Cosa save money?

We recommend that you check out our blog post titled “How Does Cosa Save Energy?” at this link to learn about how Cosa saves money.

Can I really save energy with Cosa?

The rate of saving differs according to many conditions such as the usage habits of users, home isolation, home appliances, and installation, and according to the results we have obtained from existing Cosa users, the average saving rate is 31% when Cosa is used together with combi boilers. For details, we recommend reading our post at this link.

Can I use Cosa in my home without a wireless internet connection?

Internet connection is required for Cosa to remotely manage your combi boiler and/or air boiler conditioner. During temporary problems with your Internet connection, you can switch between Home, Sleep, Outside, and User modes by pressing the top key on the Cosa Station Unit.

The warranty of my combi boiler is ongoing. Will the installation of Cosa damage the warranty of my combi boiler?

Some combi boilers may go out of warranty due to the installation of the room thermostats by a non-authorized technician. Therefore, even if Cosa does not harm your boiler's warranty, the installation of Cosa by a non-authorized service partner may put your boiler out of warranty. In this regard, we advise that you consult the manufacturer of your boiler.

How long is the warranty of Cosa?

Cosa products are under warranty for 2 years.

Can my family members or friends use the same Cosa?

Yes, they can. You can go to the Users menu by clicking on Settings in the top right of the Cosa mobile application and allow people you wish to add to use Cosa by entering their e-mail addresses. The person you invite can start using Cosa after clicking on the link sent to their e-mail address, logging into the Cosa application, and accepting the invitation. If the invited person does not have a previous Cosa membership, they need to create new membership.

If I move into a different house, can I take Cosa with me?

Yes, you can take Cosa with you. If your wireless network changes during the move, you will need to re-install Cosa.

How can I receive support?

You can get support from the Cosa Support Team. You can contact the Cosa Support Team by calling 0850 5580850 or sending an e-mail to You can also check out the Frequently Asked Questions section before you contact the Cosa Support Team.
Installation and Setup

Where can I find installation guide of Cosa Smart Thermostat?

You can easily set up and install your Cosa Smart Thermostat by following the instructions here

I saw the Home screen in the first installation, but the Cosa Station Unit is blinking blue and white. What should I do?

The blue flashing of the light on the Cosa Station Unit means that the update process is taking place. The update process may take up to 10 minutes depending on your internet connection speed. During this time, do not remove the Cosa Station Unit from the wall socket. Once the update is done, you should be able to see the main screen again with the current temperature in the Cosa application. If the problem persists, you can contact the Cosa Support Team.

I could not find my air-conditioner on the list or it does not work even though I found it on the list. What should I do?

First make sure that there are no obstacles between the Cosa Station and your air-conditioner. If there are no obstacles, you can move your Cosa Station Unit closer to your air-conditioner. If the problem persists, you can contact the Cosa Support Team.

I cannot match the Cosa Station and Cosa Heat Control. What should I do?

This may be due to the length of the distance between the two units, the walls, or the effect of other wireless devices in the vicinity. First of all, make sure that both units are at least 30 cm away from metal surfaces and that combi boiler is not between the two devices. You can also increase the likelihood of pairing by placing the Cosa Station closer to the Cosa Heater Unit or by changing the angle of repose of both units.

If the problem persists, you can contact the Cosa Support Team.

I received the 'Installation could not be completed' error and the red light is on at Cosa Station Unit. What should I do?

You may have entered your wireless network password incorrectly. In this case, try the installation again by pressing the factory settings button under the Cosa Station Unit. If the problem persists, you can contact the Cosa Support Team.

I am receiving the 'Device could not be found' error. What should I do?

First, make sure you are connected to the Cosa_XXXX network. If you are connected, but using a manually entered DNS, you will not be able to set up the device. Once you have uninstalled the DNS you are using, you can complete the installation and you can return to your old DNS settings after installation is complete.

If you are receiving the ‘Device could not be found’ error even though you do not use DNS, you may be installing an old version of Cosa. In this case, please try to install Cosa via Cosa mobile application, not the web application. The update process will take about 10 minutes and Cosa will switch between red and white colors from time to time, please wait.

If the problem persists despite carrying out this process, you can contact the Cosa Support Team.

I cannot see my own network on the list of wireless networks in the Cosa mobile application during installation. What should I do?

If you do not see your wireless network's name listed during installation, you can solve the problem or identify the source of the problem by following the steps below:

- Wait: Even if you cannot see your wireless network at first, the Cosa Station will continue to search for wireless networks in the background. After waiting for about 1 minute, you can press the \"Search Again\" button to make the Cosa Station re-list wireless networks.

- You can try to reduce the distance between your modem and the Cosa Station Unit.

- Make sure that your wireless network is not hidden. If your wireless network is hidden, change it so that it is not hidden from your modem for a temporary period of time during installation. Once you have completed the setup, you can put your wireless network back into stealth mode.

- You can try restarting your modem.

- You can try connecting to your wireless network with a different device. Try this method from where the Cosa Station Unit is so you can be sure there is no problem with your wireless network. If there is no connection with another device, you may be too far away from your modem. Move the Cosa Station closer to your modem and try again.

- Make sure your modem is compatible with the Cosa Station: Cosa Station works on 802.11 b/g standards and the 2.4 GHz frequency band. The Cosa Station unit cannot communicate with your modem on the 12th and 13th wireless channel values. Most modems have this standard as well as some very new modems that also support the 5 GHz frequency band, but your modem may just be set to work with this frequency. You can try again by changing this setting. To change the settings, consult your modem's operating manual or the authorized technical service.

- Make sure that there is no interference with other devices: This problem may occur if there is interference with other devices running at 2.4 GHz. Please turn off wireless telephones, bluetooth devices, wireless security systems, and similar wireless devices and try again.

- Try reducing the number of wireless devices connected to the modem.

- Try temporarily turning off your modem's security settings.

- Make sure your modem does not have a MAC address filter.

- Make sure your modem is using up-to-date software.

If the problem persists, you can contact the Cosa Support Team.

The blue light is lit on the Cosa Combi Unit, but the combi boiler is not working. What should I do?

Check the following items in order:

- First wait. It may take some time for some combi boilers to switch on.

- Make sure that your combi boiler is in winter mode, that the water pressure is correct, or there is no other fault with your combi boiler.

- Make sure that your combi boiler is at a sufficient temperature, such as 50 to 60 degrees.

- Make sure that the boiler connection between the Cosa Combi Unit and the room thermostat connection inlet of your boiler is correctly connected and that there is no loose contact. - Parameter settings may need to be made after the room thermostat connection has been made for some combi boilers (e.g. most Demirdöküm branded combi boilers). If you have not already done this, you can read the manual or contact the authorized technical service or the Cosa Support Team.

If the problem persists despite you carrying out these steps, you can contact the Cosa Support Team.

I cannot see or connect to Cosa_XXXX in my wireless networks. What should I do?

In order for the Cosa Station Unit to be capable of broadcasting with the Cosa_XXXX name in wireless networks, the light on the Cosa Station Unit must be constantly white. If the light does not turn white after 30 seconds after you plug in the Cosa Station Unit, you should reset the Cosa Station Unit. Press the Factory Reset button under the Cosa Station Unit once and wait for the light on the Cosa Station Unit to go and stay white.

If you cannot see the Cosa_XXXX network on wireless networks when the light on the Cosa Station Unit is constantly white, you can try moving it closer to the Cosa Station Unit. It helps if the phone or computer with which you are carrying out the installation in this phase is no more than 3 meters from the Cosa Station Unit.

If the problem still persists despite you carrying out the steps, contact the Cosa Support Team.

I could not find the room thermostat connection point on the combi boiler. What should I do?

If you contact Cosa Support Team with the brand and model information of your combi boiler, we can provide you with images if it is a combi boiler already in our database or we can help you to find the connection point by providing support over the phone.

What is the ideal temperature for my radiator water?

When combi boilers are used with room thermostats, 50-60 °C is the recommended temperature to set the radiator water to save more and reduce the time to heat your house.

What should I keep in mind while placing my Cosa Station Unit?

Please do not place your Cosa Station Unit near heat sources like wi-fi modem, TV, sun-lit areas, closed cabinets, combi radiators, doorstep and floor. The Cosa Station Unit must be positioned at a height of at least 50 cm and at most 150 cm from the floor. Try a number of different places for the ideal position.

Where must I place the Cosa Combi Unit?

If your combi boiler is inside a cabinet at the balcony, place the Cosa Combi Unit in a way that it will be positioned at the bottom side of the cabinet​

If your combi boiler is inside your house, mount it on the wall right next to it. ​For best wireless communication between the Cosa Combi Unit and Cosa Station Unit, make sure that you place the Cosa Combi Unit at least 30 cm away from the metal surfaces of your combi boiler and your combi boiler is not between the Cosa Combi Unit and Cosa Station Unit.