While water is wonderful I really don’t want it leaking into my apartment because of faulty pipes and taps. Even more so I don’t want it secretly leaking out of my apartment into someone elses. This is what we call A Fucking Disaster.
That’s why I’ve been integrating leak sensors wherever I fear water leaking. Like everything else I’m installing, these are wired devices: why not when I have all the walls and ceilings open?
These are dirt simple devices, powered by 12V/24V sent over two of four wires. A unit has two metal prongs on its underside. As soon as those prongs are bridged by water, a connection is made and the unit closes a digital logic circuit in the other pair of wires.
You need something smart to connect them to. Given that I will have one of the Kincony ESP32 boards at the heart of my house, this isn’t a problem.
Where
These are one of those areas where my home automation was ahead of my construction. While we were constructing our bathroom I had laid in wiring for these sensors, at places where I knew water pipes would come together. It’s these joins that are the most likely to leak, after all. So I had cables placed under the sink, under the bath pipes, and underneath the electric water heater and drains for the washing machine and water softener (yes a water softener - ain’t I fancy?).
When it came to finalising the bathroom I connected up the sensors in a Normally Open configuration to standard 4-wire KNX cable, and screwed them in place to the floor. When the walls went up they were invisible.
Limitations
However, wired sensors are inherently inflexible. Once the walls went up I couldn’t easily run more cables, nor change the position of the sensors themselves.
The lack of cables also means that I only have a few places covered, and all of them are behind walls. What about directly underneath the washing machine, where water is going to spill out if it borks on guinea pig hairs?
This is part of a layered strategy, so I’m not too worried. For directly underneath the washing machine I can always use battery-powered Zigbee sensors, or an ESPhome USB-powered board.
The stuff I’m really worried about is what I can’t see, and hopefully these wired sensors give me some protection there.
Doing something
So if these sensors pick up a water leak they can inform Home Assistant, which can send us alerts. That’s great if we’re at home, but what about if we’re away?
Well I’ve got that covered also. I had our plumber (for water and electricity are the two things I’m not touching in this apartment project) put in DC-powered water valve where our mains supply comes in.
By applying power 12V DC a ball valve inside it rotates, cutting off the water supply.
Hooked up to the same ESP32 board this means I can open and close the water supply remotely. More usefully I can go further and usa a HA automation to turn off the water supply automatically as soon as a leak is detected.
These things are a last resort only. Upstream from the automated valve I have a normal hand-operated valve - I don’t want to be relying on technology to do something like this unless I really have to.
So there we go - water leak detection and water protection combined into one.