August 2017 – Is the toilet running?

We want to know when a toilet continues to run after flushing.  There are several failure modes for toilets.  This problem is focused on when the flapper fails to seal properly… where jiggling the handle will fix the problem.

  • Measure resistance between contacts inserted into the bowl fill tube.  This will tell you when the water is flowing.
  • Put a switch on the flapper that tells you it is seated.
  • Connect something (e.g. stepper motor) to jiggle the handle
  • Flow sensor in water line
  • IR sensor across bowl fill tube
  • Put a switch on the float
  • Measure the water level in the tank
  • Monitor the noise of the water filling the tank
  • Detect vibration of tank filling, flapper closing, …
  • Total replacement of flushing mechanism with modern electronics, solenoids, …

We decided that a float switch that detects when the tank is full is probably the simplest solution.  The flow sensor on the water line would handle all failure modes, but most flow sensors have a minimum GPM that they detect, so there could still be leaking that goes undetected.

It is interesting that full electronic replacement of toilet mechanisms is not mainstream yet.  Probably due to cost.



Triangle Embedded Interest Group