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FRITZ!DECT radiator control often loses its connection to the FRITZ!Box

The DECT connection between a FRITZ!DECT radiator control, for example FRITZ!DECT 302, and the FRITZ!Box drops frequently. The connection status "Not connected" is displayed in the menu "Smart Home" of the FRITZ!Box user interface.

Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.

Simply proceed as described below. After each measure, check whether the problem is solved.

1 Updating the firmware of the radiator control

  1. Click "Home Network" in the FRITZ!Box user interface.
  2. Click "Mesh" in the "Home Network" menu.
  3. Click "Perform update" next to the respective device.

2 Checking the batteries

  1. Use high-quality batteries. Varta Industrial Pro AA, Varta Longlife Max Power AA, GP Super Alkaline LR6, or Duracell Industrial AA are suitable.
  2. Do not use rechargeable batteries. Rechargeable batteries usually have a higher internal resistance and a higher self-discharge rate than disposable batteries and produce lower voltages. This can affect how the radiator control functions and shorten operating time.
  3. Do not use zinc-carbon batteries. Due to their construction, they are not suitable for use in radiator controls.
  4. Do not mix new and used batteries.
  5. Remove the batteries and reinsert them. Make sure that the batteries are firmly seated between the battery springs.
  6. Check the battery level of the radiator control under "Smart Home" in the user interface of your FRITZ!Box. If the battery level is under 30%, replace the batteries with new batteries for testing purposes.

3 Turning off other base stations

  1. For testing purposes, switch off other base stations in the vicinity of the FRITZ!Box.
  2. If the problem no longer occurs then, switch off the other base station or place the base station farther away from the FRITZ!Box.

4 Disabling "Reduce DECT field strength"

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "DECT" in the "Telephony" menu.
  3. Disable the option "Reduce DECT field strength" in the section "Radio Field Strength".
  4. Click "Apply" to save the settings.

5 Removing USB 3.0 devices from the FRITZ!Box

  1. For testing purposes, remove all of the USB 3.0 devices from the FRITZ!Box's USB ports.
  2. If the problem no longer occurs then, a USB device was interfering with the radio connection. Eliminate the interference caused by the USB device.