Z-Wave "Group 2" association tuning

Configuration Z-Wave
1

I have a leak sensor and a water valve. I’ve created "group 2 " association. The sensor sends the valve a “basic set” OFF command when moist and ON when dry. But I don’t want it to ever send the ON command - doing that in a home water leak protection scenario is plain stupid.
However, the available options are:

  • don’t send anything
  • send OFF on moist, ON on dry
  • send ON on moist, OFF on dry

I checked specs of 2 different sensors, they are both like that.

Is this a Z-Wave standard problem? Do I have a hope of ever finding a sensor that lets me do what I need?

2

Unfortunately, none of your requirements are Z-Wave standards. It would be helpful to know which products you actually have though, and what your use case is for the Z-Wave water leak sensor. Researching several devices, it seems the behavior you desire is a common design for leak sensors so maybe you can find another one (see below).

Is there a reason you don’t want to involve HA and use an automation? That would be the easy solution. Maybe you want to avoid using HA in case it crashes, or power goes out? Do you have a battery backup for the valve?

Assuming your device is categorized as a Notification Sensor device type (seems to be the common case for water sensors), then in Z-Wave Plus V2, notification devices are actually prohibited from using Basic Set (“Basic Command Class MUST NOT be supported” says the spec). I don’t see how this makes any sense at all, since devices like water vales are also required to support Basic Set commands.

Groups are device specific, and except for the Lifeline (typically Group 1), are not mandatory. There’s nothing that says “Group 2” has to exist or have any prescribed behavior. The fact that your device sends Basic Set commands is a design specific to that device. It may happen to be the same behavior in other devices, but it’s not part of any standard.

Configuration parameters are also device specific. There’s nothing standard about which settings a device should have.

Finally, there’s nothing in the standard specific to Water leak sensors. There are standardized notifications (Notification CC) for water leak detection, but that notification would have the same problem (states are detected or idle), so Basic Set would work better.

As for other products:

HomeSeer HS-LS100+ supports sending Basic Set via Group 2 and doesn’t make any mention of sending dry commands, only leak detection.

Aeotec Water Sensor 7 Basic and Pro also both support a configurable Basic Set command for leak detected. These are Z-Wave Plus V2 devices, which means it ignores the standard with respect to Basic support.

This Custos water leak sensor can configure Basic Set for leak detection and cancellation independently. These are also ZW+v2 devices, and yet still support Basic.

Depending on where you are trying to detect leaks, and if replacing the valve is an option, both the Custos and Zooz ZAC36 water valves include local wired leak sensors. Of course, if you need remote detection, the wired connections aren’t of great use. These valves look identical, maybe Custos is the OEM, or they share the same OEM. Custos manuals are much more detailed.

Both Custos and Zooz sell bundles with valves and z-wave leak sensors, so you would hope they could work together. According to above, the Custos sensors would work fine with either. It appears the Zooz ZSE42 leak sensors only support on/off or off/on Basic Set commands. You could try sending them an email asking for the feature as a potential customer.

1 Like
3

My use case is 1 water valve shut off by multiple leak sensors placed around the house.

The leak sensor I’m playing with is Zooz ZSE42, I talked to their support and they suggested using a controller as a solution. However, their pdf doesn’t mention sending a “dry” command: “This device will send a Basic Set command to Group 2 whenever it detects water.” <= that’s it.

Another spec I checked was “Dome by Elexa leak sensor DMWS1”, it says:
“Group 2 The Leak Sensor sends a Basic Set command to Association Group 2 (or the Control Group) to directly trigger devices (like a light, chime, etc.) in response to a detected leak. Then, after the leak is no longer detected, a BASIC_SET(0x00) command is sent to reset the device (e.g. turn off the light.) The value of the Basic Set command (e.g. brightness of the lamp) is configured using configuration parameter 7.” Perhaps I can use this Parameter 7 to modify the “dry” value to be the same as “moist”?

My water valve is “Bulldog Valve Robot” (Bulldog Valve Robot) I chose it because it has a detached Z-wave controller that I can place anywhere in the house, while the Zooz valve has it in the valve, which isn’t going to work as I have the valve 1 foot down in the ground, 20ft from the house.

The controller is a Dell PC with “Zooz USB 700 Series Z-Wave Plus S2 Stick ZST10 700” running Home Assistant with “Z-wave JS UI”, not that it matters for my use case.

I tried an automation in “Z-wave JS” and it worked properly (I’m not sure the sensor resends the “Group 2” “moist” notification, but, hopefully, the automation periodically checks the status). This could be a fall-back plan, but I chose z-wave for its ability to work without it, as I don’t want my system to depend on a huge blob of s/w.

Thank you for suggesting these other products, as you can tell I’m just starting with this thing.
But already starting to have doubts as I found that it doesn’t work beyond 6ft! The battery in the sensor is 2 months old, the controller shows 70%. Maybe it’s the receiver (which is on the wall power). Who knows, but the situation now looks like this: after installing and testing the system, do I need to retest it every month to see if connections deteriorate with time? If the controller can receive data from the sensor it doesn’t mean the valve will.

4

Would you be interested in something like the Zooz Zen17? You can connect multiple wired leak detectors to it and you can set it up to only send the off command. Plus it’s cheaper then other options because you can get wired leak sensors for $2 each on AliExpress plus the Zen17 is $22 when on sale.

5

Thanks. Yes, your idea looks much better than many separate Z-wave sensors with batteries. But the Bulldog’s Z-wave controller also has a jack for a wired sensor. Thanks to this clever design, I have a second way to activate the valve without Z-wave. I just need to figure out how to hook up multiple wired sensors by cables maybe up to 30ft long. (Researching this now, might need a shielded cable for long runs… BTW, amazon has a $20 relay activated by a wired leak sensor - at such prices I can built 2 parallel systems for redundancy :-). I’m more and more becoming convinced that a critical system like flood protection shouldn’t be built on radios powered by batteries.

6

Is this the $20 relay on Amazon? https://a.co/d/fO2G3sk

The Zooz Zen17 relay works even if it’s not connected to a zwave controller just like the Amazon relay. Plus with the Zen17 you get 2x relays in one device. Plus the Zen17 is rated for 20A on the NO. Circuit and 10A on the NC CIRCUIT. The Zen17 outperforms any other relay out there. Then when you consider it has a Z-wave chip in it it is the best relay you can get for under $25 period.

I saw that the bulldog uses a 3.5mm leak detector sensor. Your best bet would be to open up a cable and see which wires trigger the bulldog then buy normal leak sensors and connect them to the 3.5mm cable. The kind with the 3.5mm jack are $4 a piece on AliExpress while the 2 wire kind are $1.50

7

That’s the one. I agree that the Zooz product might be a better buy. Plus, I already know that their customer service is responsive and they’ve been around the block for a while. BTW, Bulldog customer service is also pretty quick. They say it’s a 2.5mm jack. I just need to figure out the electrical side - what kind of device and cable topology I need, to gather signals from several sensors around the house (sometimes long distance) and feed into this 2.5mm jack. That jack is for a typical wired sensor where water creates an electrical path between 2 contacts - but I’m not proficient enough in electronics to immediately know how to connect many, sometimes distant, sensors to it. But I’m working on it.

8

BTW, Since Zen17 has a z-wave chip and z-wave control, wouldn’t that mean that the chip sits between the sensors and relays, and there is no purely electronic circuit that translates sensor state into relay state? Probably software inside the chip watches the sensors and activates the relays, plus z-wave commands probably can override that control. Does this make it less reliable? :slight_smile: I don’t know. But it’s way more complicated than a non-z-wave device.
BTW, Bulldog customer support says the NO output of a relay can be fed into the Bulldog’s 2/5 mm jack, so I can install such powered relay in each bathroom and connect by long wires to the same 2.5mm jack, so when one relay closes the output, Bulldog will “sense water”.

9

So the Zen17 works even if you don’t have a z-wave network. This is why it’s the best relay you can buy on the market. However once you add it to the Z-Wave network you do get more configuration options and more functionality.