McGyver flood sensor

Hi all, just wanted to share a little project I did today.
Having had a couple of close calls with flooding, I went and bought a couple of Samsung leak sensors ( They are affordable as well as they have that extra set of sensors on top. You see sensors? I see soldering points :slight_smile:

Anyhow, I placed one of the sensors inside the house without modification, yet the other one needed a bit of tinkering, as I was going to monitor the sewer line with it. We have a service port for the sewer outside, hidden under a hideous plastic rock. The pictures probably speak for themselves, yet here’s a brief breakdown

  • Drill two holes in the cap to fit the diameter of some regular 16 gauge stiff copper wire.
  • Mounted the sensor on top using double-sided velcro.
  • Cut off two pieces of copper wire long enough to stick a decent length down the sewerpipe.
    (Mine was about 3 feet deep, so I settled for going half way down)
  • Strip off about an inch of insulation at one end. Strip off about 1/8" at the other.
  • Shape the wire ends sticking out of the cap to touch the sensor pads on top and solder them in place
    (Be nimble and quick about it, you don’t want to bust the sensor by overheating it)
  • If your sensor wires are longer than a few inches, you might want to consider crafting a spreader like I did.
  • Optionally, epoxy the wires in place in the cap. I did it to reduce any stress on the soldering points.
  • Presuming your sewer port is outside, find something to cover the contraption with, as you don’t want a false alarm next time it rains!

I suppose a snafu with this setup, is when it’s time to change the battery in about half a year, I’ll have to break out the soldering iron. I’ll probably pick up a couple of screw terminals at Fry’s before then.

McGyver Sewer Flood sensor

Sensor mounted in place

Hideous plastic rock in place. Job done.


Nice, I. did the same with one of mine but used the bottom points to dip the wires into a sump pump basin. That way if the water gets too high I know the sump has failed. I used one of the rubber caps as pasthough


I have one of those access ports close to the house and one close to the road. Are those the same thing you are monitoring? What is the alarm telling you when it goes off? Backed up sewer line? If so, what would be the action item to prevent sewage from flooding your house? Not having ever dealt with this type of issue, I am not sure what you are trying to prevent. I am looking for an excuse for yet another sensor :smiley:

Hi aruffel,
Completely agree, one can only have one class of sensors: Not_Enough! Wifey suggested (rolling her eyes), that I might consider switching to heroin as a hobby: It’s both cheaper and less addictive than IOT :smiley:

Anyway, to answer your questions, yes it’s the port close to the house I’m monitoring. Since it has the long leads down the pipe, it tells me the water is now rising and there’s still about 1½ foot before it reaches the top (i.e. the house)

As for actions, it’s sirens and push alerts for now, before I get a shutoff valve for the main line. However I’m adding an Aeotec heavyduty relay to override the pool pump as well. The first leak we had, was caused by the poolguy backflushing the DE filter!

As the water entered the house through the drain of a downstairs showercabin with a 5 inch basin, I’m banking on this together with the port sensor, will give me enough heads up to cut the water, roll up my sleeves, hold my breath and go to town on the port with a hose and a plunger. It’s nasty as hell, but beats having the house flooded.

Hope this helps to clarify