Connect Karl & Karl big with the Stadler Form App

Here, you'll find out how to connect your humidifier Karl, or Karl big, with the Stadler Form app. Monitor the air quality and control your humidifier from anywhere.

Important note for Android users
In order for your Android device to establish a proper connection to the app, you must make additional settings on your Android device.
Click here to access the step-by-step guide.

The Stadler Form App

With this app, you can make even more efficient use of your Stadler Form indoor climate devices. Control one or more Stadler Form devices remotely. To control devices that have Wi-Fi capability, you need the app as well as an account. Download the app from the App Store or via Google Play, install it, and register.

Download the app and open it. If you already have an account, you can log in using your user data. If you're new, you'll need to register first.

Make sure that the Wi-Fi connection and Bluetooth on your smartphone are enabled. Select the Wi-Fi network you'll be using to connect the device later. 

Turn on your Karl or Karl big. Ensure that the LED at the bottom of the Wi-Fi button is flash. If the dot isn't visible or does not flash, press the Wi-Fi button for 3 seconds until the dot starts to flash rapidly. To see the LED, you must stand directly above the unit and look down.

Karl or Karl big will now automatically appear in the app under "Discovering devices". Simply click "Add," wait until he's connected, and you're good to go.

If Karl or Karl big doesn't appear automatically, click the "+" icon in the top right corner of the main menu, then select "Add Device."

Next, choose Karl or Karl big from the overview.

Afterwards, select a 2.4 GHz Wi-Fi network and enter the corresponding password.

Karl or Karl big must be in pairing mode for a connection to be established. According to the app, check that the LED on the bottom of the Wi-Fi button is blinking. Once the LED is flashing, confirm this and click "Next."

Now, the pairing process begins. After a few seconds, the LED on the bottom of the Wi-Fi button on Karl or Karl big will stay lit steadily, indicating that the app has located the device.

The device is now added to the app.

Karl or Karl big is now connected and successfully added in the app. Click "Done" now.

Done! You can now control Karl or Karl big through the app. By the way, you can exclusively activate the child lock in the app. This feature prevents the buttons on the device itself from being operated. 

Note for Tuya app users
If you have been using the "Smart Life – Smart Living" app from Tuya for your Stadler Form devices, you can continue to do so. However, it's not possible to have a device stored and operated in both apps. We recommend switching to the Stadler Form app, as it will be further developed to provide an even better experience in the future. Please note that when you switch, you'll need to create a new account for the Stadler Form app and re-register your Stadler Form devices.


Only one account can be connected to the device.

In your Stadler Form app account, however, you can share access to control your device with other people. To do this, go to the desired device, click on settings in the top right-hand corner and select "Share Device". Here you can grant access.

  • Restart your mobile phone

  • Switch off your router or Wi-Fi, wait 30 seconds and then switch it back on again. Then you can try again to add Karl or Karl big automatically, as described in the instructions

  • If a timeout still keeps occurring, add Karl or Karl big manually

Important note for Android users
To connect correctly to the app, you must make additional settings on your Android device. Click here to go to the step-by-step instructions.

Karl or Karl big can be disconnected from the app quite easily. Go into the app and delete the device. Or alternatively, hold down the Wi-Fi button on your humidifier for 3-5 seconds. When the button starts to flash, you know that your Karl or Karl big is no longer connected to the app.

If the LED below the Wi-Fi icon is solid, your humidifier is connected to the app.

After you have connected Karl or Karl big to the Stadler Form app, it will take a few seconds for the measurement data to be displayed in the app.

No, Stadler Form devices can't currently be integrated in the HomeKit.

Make sure

  • that your Karl or Karl big is connected to the power supply correctly and switched on
  • that your smartphone is connected to WLAN and Bluetooth
  • that the wireless network is enabled on Karl or Karl big. If not, hold down the Wi-Fi button for 3 seconds