Measuring water level with Z-Wave

We were looking for a way to know the water level of the water tank via a Smart Home controller (via Z-Wave). Or actually we wanted to know if the water was almost empty so that we can refill it. A pump is connected to the water reservoir, which provides water to the plants in a greenhouse. If the pump runs dry, it can break, which is of course a shame and the plants also dry out.

The water pump is already connected to the Homey, so it can be turned on or off remotely. So now only a solution for the water level.

Simple cheap solution

After some google work, we came across various solutions that could measure the water level with a lot of hassle. We thought this was a bit too complicated and it must be smarter and simpler, right? Via AliExpress we came across a float that opens or closes a connection via a make contact. If there is no water, it will let electricity through and if there is, it will not. This seemed like a simple solution to us.

Various sizes of this float are available and you can buy it from 2.50 via this link.

Now something to connect to this float.

We arrived at a Neo Coolcam Water sensor which works via Z-Wave. It also has contact points that allow current to pass through when they come into contact with water. We can connect the wires to this quite easily.

Step 1:
Buy a Neo Coolcam water sensor.

Buy the Float.

Step 2:
Add the Neo Coolcam sensor to your controller and test whether it works properly.

Step 3:
Find out what the plus and minus is on the Neo Coolcam sensor. There are 3 contact points on the bottom and this differs per type which they are. You can find out by measuring with a multimeter or making a wire that you connect to the 2 points to see if the alarm goes off.

Step 4:
Connect the wires from the float to the correct contacts on the sensor.

Step 5:
Install the float and controller or it works by bringing the water level below the float.

Example flow:
Finally, we create a flow that sends a notification when the alarm goes off and we make sure that the pump does not start.

Perfect solution:

We have been running this solution for a few months now and it works perfectly. You can of course also use it to measure the level of your rain barrel. This float can be completely submerged, so a version with a rod that is too short is not a problem if your water reservoir is higher. Make sure that the wires are not super long.

Finally, we would like to report that we use a Neo Coolcam Water sensor, but this can actually be any water sensor (such as a Zigbee variant). We chose the Neo because it has many configuration options.