Water Leak Sensor SmartThings - Reverse usage

Just wondering if anyone has any experience on reversing the usage of a water leak sensor, in particular with Samsung SmartThings? I have a place where I always want water in there, so I use the water leak sensor to monitor and let me know if it is dry. Just wondering what is the logic inside the device? Would it keeps sending the signal when water present? So, the battery will drain in a day or two? (not going to work for me). Or it will send the signal once when wet and send another signal when it is dry again? In this case, the battery will last for a year. (this will work for me!). Any different for z-wave model vs Zigbee? Thanks!

I was thinking about something similar and posted on this a while ago.
I believe the general consensus was that the device always being wet would indeed drain the batteries and likely cause potential problems with the contacts.

Can you elaborate on what the application is?
Perhaps there are other options.

there are water leak zwave device handlers out there that you could easily modify to reverse the logic or even add custom attributes that you could handle.. generic contact sensors also work on water sensors at least the ecolink ones so you could use those.. just not sure about the battery life if they are continaully alarming. i think ecolink would be ok as their water sensors are just normal contact sensors seince they have a slot to plug in an external probe

I wonder if using a contact sensor with an external contact (like the WADWAZ-1) could help. drop wires in the water on opposite ends, which theoretically the circuit should complete and mark the sensor as closed. Then when the water dries out/runs low, the wires wouldn't have a path and then be open

Thanks all for the quick response! My application is very simple, I want to use it as a physical wire open/close switch. Not really involved with water at all. My scenario is like this. I want to detect motion and turn on my hallway light for few minutes at night. However, there are 3 different ways to enter my hallway, from basement, from 2nd floor and from kitchen. So, I will need to have 3 motion sensors, one on each entrance point. I tried to put a Zooz motion sensor in the middle of the ceiling. However, the detection angle is so small. (Spec said 120 degree, actual is less than 90). I also tried to put in a Ecolink on one corner. It covers 3 corners well, but walk from underneath will not detect motion until I reach the other end. My hallway currently has a DSC motion sensor that hook up to my old DSC alarm system. This unit covers all areas well, but it is NOT zigbee or z-wave. It has 4 wires, 2 wires supply 12V from the DSC panel, the other 2 wires actual sends signal back to the alarm unit. This 2 wires connect when no motion. Break when motion detect. This is exactly the opposite behavior of a leak sensor. And indeed, I tried to hook up a Dome Leak sensor to test it out. And it works. So, I am thinking to hook it up this way with a smaller leak sensor (SmartThings), let it sit on top of the DSC motion sensor, So, I am using the motion detection from the DSC, pass the signal to me leak sensor and send to HE. My concern is: will the battery get drain in a day as it is mostly connected (wet).
@dadarkgtprince, I think your idea of WADWAZ-1 likely will work. I did not know there is such kind of contact sensor with external connection. Thanks for suggestion. Do you know any other contact sensor with the same external connection? The WADWAZ-1 is older model and expensive. Need to find out if I can still buy them in Canada.

Not the cheapest but certainly the easiest device to use.

Zwave Plus Door & Window Sensor (DWZWAVE2.5-ECO)

@Ranchitat, do you know if this Ecolink contact sensor you recommend has an external connection? I can't see that in the manual. But the price is much cheaper.

It's that white block above the battery in the pic above.

Also if you scroll down and look at the "customer images" you can see a better image.

Thank you Ranchitat. I see it now. Ordered one from Amazon already!

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:+1: Hope it works for you.

P.S. What you're looking for is a "Dry Contact Sensor", a set of contacts that generates a Zigbee or Z-wave signal.
Not to be confused with a "Dry Contact Relay", a set of contacts controlled by a Zigbee or Z-wave signal.

If you search the forum/web you'll see many examples of people modifying door/contact sensors to work as a "Dry Contact Sensor". Which can be had for quite a bit less (10 Zigbee for US$50) than the Ecolink or GoControl.


i use this ecolink with this setup as a sensor to detect power outage in the house..
works great.. i also can sense when power is restored and send a message as long as the hub hasnt been shutdown to a TOO long outage.
it uses the above mentioned conact wiring on the ecolink sensor.

Unfortunately that is unlikely to work as in my experience it takes a while for the sensor to dry out after it has been wet. Also, battery life is likely to take a severe hit.
I have a water leak sensor just inside a window I always forget to close, it reminds me to shut it when it starts to rain. Even after a small amount of rain (well, small for the tropics) hits it, it can take several hours to dry out and return to normal if left alone.

if you have 12V power there, you could try a ZEN16 as that's powered by 12V DC. this will help alleviate the concern of batteries

It really depends on the sensor and if/how it's modified. Some sensors may have some kind of foam or other material that saturates with water, expands, and eventually pushes a physical button to signal a wet condition. That type of sensor would indeed take some time to dry out. But something like the SmartThings Leak Detector works simply by water completing a circuit between 2 contact pads that are quite close together. As soon as the circuit is broken again (dry), the sensor sends a report. The response is pretty much instantaneous.

The problem I have found with the SmartThings sensor is that it's not raised high enough, so if water gets underneath it, it becomes trapped and takes forever to dry out. Even then, sometimes when I dry off the entire of the external body it still detects water. It looks like water may leak inside through the hole where the sensors poke out.

Ah. I see what you mean, although I'm surprised that water would be getting inside them. I've never had one of mine in enough water that that could have happened. But, if I were going to use one of these as a reverse sensor, what I would do is solder a couple of wires to the contact pads, and then have only the wires in a place where they'd get wet.

The eco link sensor dries out immediately as the water needs yo touch both probes about an lunch apart to complete the circuit. At least in ky experience you need a fair amount of water for that.

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