Manual misleading

A nice and good smoke detector, already widely described as here ....
... Only, my first was not working when I tried to described the functional test as described in the (complicated) manual run.

So:
Insert battery -
- Close the lid
Press button for 4 seconds -
- Get acknowledgment and red light, but there is no fire drill

Repeat with new battery brought the same result: no alarm

Did the device already return as "defective" when I thought about calling (very friendly and competent) Hotline at the Gira. There I learned that instead of that in the manual four seconds as long as is necessary to press the Tate until the sample alarm sounds. And sure enough, he came! Just why that is different from the manual, not the friendly man knew.

Conclusion: Good tool, stupid description. Therefore only 4 stars