This is just an example and not a question - hopefully it helps others. I have old toilets and they get stuck refilling forever sometimes because the flapper gets stuck with the chain or the fill valve arm gets stuck. I won’t know it’s running for hours sometimes wasting water. This example could also work for rain barrels or anything else that needs to detect a dry condition
I was worried that sensors that detect water will keep sending a ‘wet’ condition and run down the battery. However, it APPEARS, so far, that the Aqara Zigbee water leak sensor only sends state changes. I’m still watching them but the battery has remained stable. I attached leads to the bottom of the sensor and ran them into the toilet tank so as not to submerge the actual sensor. This seems to work fine and I made an automation to send me an alert when it’s dry for more than 3 mins rather than wet - the toilet refill takes 1 min so anything over is an issue that needs to be dealt with. Works good. I’ve attached pictures.
I used the smallest lug crimped terminal for the bottom of the sensor (the screws are a small hex and can be removed and screwed back on with the lug), a crimped ferrule for the water side with shrink wrap to somewhat waterproof it. I used that real good 3m tape to attach the sensor to the outside of tank (a small square).
The one you describe there the bottom exit point is not blocked after the cistern is emptied.
The other one is the one I most often encounter, which is where the valve that is controlled by the floater is not closing so the water raised up and exits through the overspill.
My thought is to put it inside the cistern and let is monitor the flow. I also have a stepper motor that flushes the toilet so I know when it flushes. My througt is to send a message to close the valve if the flow does not stop a certain number of seconds after a flush.
What we typically get here, is the valve gets a little stuck (the black thing with the red cap shown) and even the water is supposed to lift it, it gets ignored and keeps running. I don’t know if it’s a defect or hard water or something else. These are vintage toilets with new parts but that valve arm gets stuck occasionally on ALL of our 3 toilets. I just have to open it up and lift that arm manually once, and it gets unstuck and starts working. The automation just alerts me to an issue so it doesn’t run for a while unattended.
