How to make an indication of the flow of water in a pipe on avr?

Question

Microcontrollers

Good day, comrades of Tostor, the problem is as follows, there is a water pump (a stupid piece of iron that can’t do anything but pump water), somehow without interfering with the system (read without welding anything extra on the pipe) it is necessary to determine that the pump is faulty (if all of a sudden), I stopped at that to check whether water is flowing in the pipe, but how, I have no idea in my soul, all of a sudden someone has something on their mind

Answer 1

The solution "on the forehead" is a liquid flow switch. The rest is dancing with a tambourine.

Answer 2

If you do not interfere with the system, then only an ultrasonic sensor, but this is difficult and expensive. Cheaper mechanical sensor, but it must be built in

Answer 3

Put a home water meter after the pump. They are with a reed switch inside and a known number of pulses per cubic meter.

Answer 4

Maybe it's worth controlling not the water, but the current consumption of the pump?

Answer 5

Maybe by the noise of passing (flowing) water ....

Answer 6

the current of the pump motor and the temperature at the inlet and outlet, as indirect indicators, but it is more reliable to put pressure sensors at the pump outlet or a flow switch if the performance is low.