Submersible water pump with overheat protection

Hi,

Last summer I developed automatic watering system for my garden. I use mini submersible 12v water pumps and soil humidity sensors. All worked fine and the only issue was when water level in a tank drops below the leverage of pump, the pump breaks.

Can you please recommend some good, reliable, submersible water pump with overheat protection, e.g that can be run dry?

Of course, there is also the solution with some kind of water level sensor, but it cannot be submersed in water. If there is some water level with plastic box that can be submersed into water, that recommendation is also welcome, so I can implement switching of the pump as soon as it goes out of water. But here I also see some possible limits and constraints, so the pump with overheat protection would be much better in my opinion.

Thanks in advance,

Amer

Why, if you can submerge the pump, why not a level sensor?
Here is a submersible switch that they use with submersible pumps.

You place it at the bottom of the tank, with the tether anchored to the bottom of the tank, it will try and float up, a switch inside will close, when the level lowers eventually the unit will float on the lowered surface in a different attitude, the switch turns OFF.
Google;

submersible level switch
There are some expensive pressure types but also inexpensive float types.

Tom... :smiley: :+1: :coffee: :australia:

The pump quit for TWO reasons. The first you are correct about the heat, but the second reason it the bearings on the motor require water for lubrication. Without lubrication, the bearings will seize.
I have a bird bath with a submersible pump and after going dry a few times, the motor fails to turn because the bearings are ruined, and then I have to replace the pump.
Paul