[RELEASE] An alternative multipurpose Visonic Door/Window Sensors DTH + sensor modification instructions


Here is an alternative multipurpose Visonic Door/Window Sensors Device Handler. There is a discussion thread about this sensor here

I was originally posting this DTH in the thread, but someone suggested I should start a new thread to make it easier for comment and searching. So here we go.

With some modifications, the sensor can be used as

  • leak/water sensor
  • smoke detector (for wired smoke alarm)
  • tilt sensor to use for mailbox sensor or garage door sensor

Since they are only $10 a pieces, I can afford to put the modified leak sensors in every room which may have water problem in my house. Comparing spending like $30 a piece for a real water sensor in the market.

And if you already have a wired smoke alarm system, you can connect them to the visonic sensor and report status back to smartthings. You don’t need to replace them with smart smoke alarm just for that purpose.

And here is the screenshot when it is being use as different sensor function

And here is the device handler

And I also included the instructions for modification here



I would love to use this as a leak sensor, but how does it work physically? How does it detect water? Thanks

Hi Imd569

After the modification, the two exposed wires will be open under normal condition. When the two exposed wires make contact to water, since water will conduct electricity, the water will connect the two wires like closing a contact. Once the sensor detect the wires are connected, it will trigger an event to smartthings and alert you there is an water leak thru the device handler.

Ok thats would I could not find… The modification Procedure. Maybe I missed it I will click like k again. Thanks. Can’t wait to try this


The instructions are under the github page.

Just click on the the files

Leak_Sensor_Instructions.md, Smoke_Detector_Instructions.md, Tilt_Sensor_Instructions.md

I’m curious how well the leak mod works. How sensitive is it? Water doesn’t conduct electricity like metal does, it isn’t as conductive.

Does it work as well as any other leak sensor that is designed for the task?

It works very well. They warn me about my refrigerator leak and water filter leak before causing bigger issues.

Water not conduct like metal does, but good enough to trigger the sensor. You can try it out after the modification by dripping it over a big drop of water.

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@xamindar - The Samsung ST leak sensors I have work the same way…they have two metal studs on the bottom, and when they are both in water the circuit closes and the device reports “LEAK!”

I’ve never seen another type of leak detector…what did you mean by “Water doesn’t conduct electricity like metal.”

Hi Danabw

I think he is talking about conductivity of metal versus conductivity of water. It is the measure of how easy electricity can pass thru an item. For metal is about 50 while for water it is about 1, so there is an order of magnitude different, but still it is good enough for the sensor to detect the two pieces of metal are connected together.

Yes, thanks, I knew that much…was just wondering if we don’t use water to detect a leak, what can we use? :slight_smile:

Just completed my first Visonic Leak Detector! :smiley:

And I added an improvement (I think).

Rubber feet! They keep the side of the unit opposite the sensors from sitting directly on the ground/in the water if there is a leak. :slight_smile:

Thanks, @pakmanwg, this was fun and it will be useful. :smiley:

One thing to note for folks doing this - the part of the wire you cut through is actually enclosed in a tiny bit of glass, so you’ll want to cut it where you can catch the small broken bits that will fall off. then I used some needle-nose pliers to “crunch” any remaining glass bits off the wires. Very easy to do.


Look great. Thanks for the pad addition idea.

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This is a very creative idea…you should buy yourself an extra sensor to celebrate. :smiley:

I know I will :wink:

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I definite will buy more if they are discounting the sensor again!


Where did you pickup the smoke detector relay?
My house has wired First Alert smoke/co2 detectors in it. Not sure how to determine what relay is compatible.

I have first alert too. I am using this one

Thank you! A question about the wiring: did you just splice into (wire nut) the detector wiring to power and signal the relay to close the contact?

One more thing. Do I only need one to hook up to one detector to cover the whole house which has 8 detectors installed?

The sensor has it own power, so I just solder the two exposed wire to the normally open and the common end of the relay. It may be easier if you solder two long wires to the sensor and then use wire nut to connect the two long wires to the relay.

On the other side of the relay, you need to figure out how your alarm is connected and connect the three wires to your alarm.

4, 5, 6 are hot, neutral and communication. You need to figure out which one is which.

You only need one sensor for all 8 alarms you have assuming they are all wired together.

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Picture of my sensor attached to the relay. Thanks @pakmanwg for the idea and help!

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Everything is wired up and working as expected with ST however I’m having an issue with Actiontiles. The clear state looks normal but when smoke is dectected, the tile does not light up and the icon changes to a “?” with the word smoke below it. Any ideas how to correct?

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