Transmitter is not intended for "outdoor"

They worked the first few days / week also just fine. The screen is clear and displays the indoor and outdoor temperature correctly.
The operation is simple.

Eventually, it has displayed at both stations no external value. Then we changed the batteries in the transmitter and the station. This did not bring the desired success.

A request from the manufacturer TFA Dostmann revealed then the following solution:
Transmitter and station batteries removed,
the device's internal juxtaposition,
3 hours waiting and then "reinstall"

It worked flawlessly. Yet again a few weeks later the transmitter gave up the ghost. Or rather, it has been sent no signal. The transmitter itself showed the values ​​correctly.

We have our transmitter attached very protected (roof is present and no weather page).

Our guess is that the ever-present moisture still penetrates into the transmitter and its signal interferes inwards.

We will now have to give back this device - a pity.