Build This Handy Leak Detector For $1.02

You’ve probably noticed that modern life has become rather complicated, and the projects we cover here on Hackaday have not been immune to the march of progress. We certainly aren’t complaining, but we’ll admit to the occasional wistful daydream of returning to the days when the front page of Hackaday looked more MacGyver than Microsoft.

Which is precisely why this hacked together water alarm from [dB] is so appealing. Dubbed the “SqueakyLeaks”, this gadget started its life as a simple wireless intruder alarm from the Dollar Tree. When the magnet got far enough from the battery-powered base, a 90 dB warble would kick in and let you know somebody had opened a window or a door they shouldn’t have.

But with a little rewiring and two Canadian pennies serving as contacts, the alarm has been converted to a water detector that can be placed around potential leaky appliances like the water heater or in areas where you want to be alerted to water accumulation such as sumps. They’re basically “set and forget”, as [dB] says the three LR44 batteries used in the alarms should last about two years. Though with a BOM of $1.02 CAD, it’s probably cheaper to just make multiples and throw them out when the batteries die.

This project is a quintessential hardware hack, with nary an Arduino or Raspberry Pi in sight. Even if you don’t lay awake at night worrying about leaking water as [dB] apparently does, you’ve got to appreciate the ingenuity and thrift of this solution.

Of course, on the other end of the spectrum, you could always build yourself a complex system that sends you email based on high water levels or malfunctioning pumps. Whatever works.

23 thoughts on “Build This Handy Leak Detector For $1.02

    1. I also would not like that, although I also do not like this over extremist, alarmist, religious, climate change hysteria. I don’t like useless wasting of finite resources, but what the climate extremists require, is not less than a far reaching change of our lifestyle.
      Therefore just say NO to Greta and their requirements!

      1. “…what the climate extremists require, is not less than a far reaching change of our lifestyle.”

        Our lifestyle is the actual source of the climate change…

        What if the “extremists” are just trying to prevent a return to the stone age by suggesting a change in our lifestyle. A slight change to prevent a forced major one is not a bad deal.

        So yeah… let’s say no to Greta now, let’s act like good Baby-Boomers and use-up everything now and leave nothing for the future generations.

        1. “A slight change to prevent a forced major one is not a bad deal.”

          They’re not asking for a “slight change”. They’re requiring a return to the stone age to “save the planet”. Except for the elites at the top, of course. They somehow believe they will still live a modern lifestyle while the rest of us subsistence farm. No this is more about a power and money grab than any actual climate crisis. Once you control energy production and energy use of all industry, you control everything.

          Go look at some videos on Tony Heller’s YouTube feed if you want a skeptic’s view with some actual data.

    1. They just the things on these Chinese door alarms, etc. They’re way cheaper than the water alarms; 10x cheaper at least. I have one open thinking about redoing for a button release alarm.

  1. Used to make these with a Radio Scrap NPN Darlington transistor, battery or wall wart supply, sonalert, and couple resistors. If anything they are overly sensitive but totally reliable. In use more than 25 yrs and still get a chirp or two when after a rain a wet bug walks across the sensor pcb. Saved me ONE time when a leak developed, but really happy it alerted me in that case.

    Always a couple places in any house that it’s very worthy to have leak sensors in use. Definitely a good project for any hacker. Pay attention to longevity and reliability.

  2. Interesting hack. So if I wanted add a 60 second time delay for it to sound, how would I go about that. For instance, if using a simple R/C diff circuit where would it be inserted?

    I’m thinking of turning that basic cheapo alarm device into a beer fridge door-ajar alarm.

  3. I just bought a couple of these sensors from my local Dollar Tree. It appears that the new version of this sensor uses a hall sensor. When a low signal (open leads / contact, magnet far away) is sent to the chip, it is in the alarm state. When the signal is high (3v) it is NOT in alarm state. I can’t seem to figure out how to rewire this so that open leads (low signal) the unit is not in an alarm state.

    Images of the new version can be seen here;

    Any idea if I could put the “penny” sensor in series with the power switch to trigger the alarm (as in normally open).

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.