Submersible water pump with overheat protection


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,


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.

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.

Thanks. I'll do something like this SIMPLE Arduino Float Switch Tutorial!! - YouTube

Would this work fine:

I see switching voltage is 100V DC. However, I understand that it will switch 5V if powered with 5V, so I could put one write to Arduino ground and another wire to Arduino analog input to detect when float switch in water?

Thanks in advance,


Hi, my float switch finally arrived and now all is cool. The main challenge is how to glue the float switch to a submersible pump and how to glue the pump to the bottom of water tank. What do you guys recommend? All are plastic materials...

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