Toilet Water Running Alarm (or How to Avoid a $15,000 Water Bill)

Every homeowner has had the thrill of noticing a running toilet.

How long has it been on? Who did it? How could this happen? Was it me?

No matter how much you adjust the flapper and chain, this can happen to any toilet. I had been frustrated by this problem for years and wanted a solution to alert everyone when there is a problem.

This homeowner in Natick, MA experienced an extreme problem and faced a $15,000 water bill!

https://www.cbsnews.com/boston/news/natick-water-bill-15000-property-owner-william-kourtis/

Solution requirements:

-professional appearance

-battery powered with lifetime of at least 1 year

-visual indication circuit is functioning

-visual and audio alert when toilet is running

-auto reset when water is properly filling tank

-reliable

•3D printer

•breadboard and jumpers

•soldering iron

•circuit board

•555 timer

•Piezo-electric 5 V buzzer, Adafruit P1356

•2 LEDs: Green & Red with built in resistor, for example

Edgelec 12 V small LED- #X0023JMK2D

•Capacitor 470 micro F

•Resistor 47 K Ohms

•Plug- Milapeak DC 5.5/2.1 mm

•Float Switch - Anndason Model DP5200

•Holder for 4 AA batteries (and 4 AA batteries!)

The circuit is designed using a 555 timer. These IC's are incredible to use for many applications. A delay on timer is a straightforward use case.

The system uses a float in the toilet tank to detect water level. When the water level drops, the circuit is powered on.

At power on, a green indicator lights to show system is functioning properly.

If the toilet is working properly, the tank will start to fill and the circuit will shut off.

If the toilet is not working properly the tank does not fill to shut the circuit off. After 25 seconds, a red LED lights and a buzzer activates. The visual and audio indications alert the problem clearly.

Once the toilet is adjusted and the tank starts to fill properly, the circuit is shut off and resets.

The first step is to make sure the circuit is configured properly prior to soldering. Best practice is to use a breadboard.

Configure the breadboard and watch the video above to complete your proof of concept.

Once the breadboard proof concept is complete, you are ready to proceed with soldering the circuit. Lay out your components and keep jumper wires short and neat. Solder the circuit and perform another proof of concept to verify functionality.

The enclosure consists of 3 pieces: box, hanger, and cap. The 3 piece construction allows for an easier print process and is simple to assemble. The pieces will mate together and there is no need for glue. Use you color of choice and match the commode if possible.

Next, assemble the float switch in the toilet on the toilet tank stand pipe. I used a piece of 3/4" PVC trim to hold the float. Cable ties above and below the PVC trim hold it in place. You will need to adjust the height of your float based on the tank fill rate. It will take a couple flushes and is very straightforward.

Insert your circuit board and battery holder into the box.

Put the hanger on the side of the tank and connect the float switch to the circuit.

A test flush is recommended at this point to check everything is a go.

Once the alarm is functioning properly, replace the tank cover lid and put the cap on your alarm enclosure.

Let the family know about your latest accomplishment to avoid a panic the first time the alarm activates.

Sit back and relax, you will not be getting a $15,000 water bill!

Finally, let's check the design criteria.

-professional appearance = OK

-battery powered with lifetime of at least 1 year = OK

-visual indication circuit is functioning = OK

-visual and audio alert when toilet is running = OK

-auto reset when water is properly filling tank = OK

-reliable = OK