Thank you for your answer. I will look into that today.
With “maze” you mean the print itself (“sensor parts”)? I saw this morning that there is big scratch on the print, could this (also) be the problem?
@robertklep. I don’t have a multimeter, so cant check it…
If you don’t have a multimeter: if you remove one (or both) of the connections to the sensor PCB, does the alarm state change back to “no alarm”? If so, your sensor is likely broken (it has a permanent connection somewhere; the scratch you mention might be causing it).
Yeah… started to use term “sensor”, but this collides - the same for a electronic part and the sensing part.
So, because of that i used the “maze” for sensing part (as the printed circuits ??? on top of it are like a maze walls)
About scratch on top of “maze” - yes, of course, if the conductive tracks from different poles touch, then there is no need for raindrops to activate alarm.
If I remove one of them, the alarm stops indeed.
I will try a new sensor, thank you!
Just an update of my earlier post.
I put a new raindrop sensor on the aqara watersensor, and no false alarm. So my earlier problem was a defect raindrop sensor.
But i noticed that it takes a while for the alarm stops. I tried it with a few drups and I’m an hour further, and the alarm is still on. When I dry it myself the alarm turns off. Do you guys experiencing the same?
Hi,
yes, the alarm stays on if there is still water on the sensor.
At summer it’s not the problem. It will dry fast. At cold days with high humidity, even due will raise the alarm.
For normal rain, I put a piece of aluminium tape at the bottom edge. So the water will not stay at the border but drips of.
Thank you for your response. It is not the most reliable system then, that’s too bad. I wanted to use it, when it rains and the windows are open, that i get a message threw google home speakers. I use buienalarm now, and think i will continue use that.
How do you guys use yours in a flow?
Maybe my set-up isn’t really the best way either, it looks very awesome do 
.
But with many things in life, looks are not everything ;).
You could try removing the entire edge on the lower part of the housing that holds the sensor. You have added a slot to it, but that may not be enough to prevent water from building up and bridging the contacts.
I’ve used this sensor before for a flood detection circuit. In my experience, they don’t have a long lifespan. There’s a small voltage between the detection traces which resulted in heavy corroding. In less than a year the traces where broken.
I was thinking to remove the entire part that holds the sensor and place it different (more straight and open), maybe that helps. Thanks!
The lifespan is not that important for me, reliability is. I bought a couple of them for €0,55 each. But if it isnt reliable it’s a waste of (mostly) time ;).
I’ll be ordering one of these soon. The rain sensor works optically. It’s expensive, but it should work. My plan is to connect the sensor to a binary sensor and to transfer the information rain yes / no to Homey.
Looks good, but have you seen the estimated shipping costs? , very high prices.
Thanks Robert, just also found the dutch site myself.
These sensors look a good reliable solution.
This could also be an alternative if you are using a Homematic gateway (CCU2, CCU3, RaspberryMatic).
This sensor is also a bit “home made” because this is a DIY kit… 
are you sure you don’t have a range issue? Is it still connected to homey i mean. if you take off one off those wires it should go out.
Yes, it is not a range issue. I already figured it out. There was some water behind the sensor, so the alarm was triggered every time.
Yesterday I changed the part the raindrop sensor was in (using the other side). No false notification for now. I will keep monitoring it for I while, before using it in a flow.
did you make this out off PLA or PETG. My first was PLA but after a year it was totally out of shape
