[invalidator]

I love ESPHome. The declarative language makes it fun and easy to do so many little tasks like this. Used with Home Assistant it makes it easy to create graphs of everything. Do I NEED to know how much water my tree consumes? No, but I like seeing it anyway!

When controlling physical systems I try to limit the damage they can do with simple interlocks. For instance, the relay I added to control my central heat is in series with a conventional thermostat which is set for a few degrees above pleasant.

Likewise, you can splice a float switch in line with the pump's power cable, positioned so it will cut off power if the water level nears the top of the tree stand. This will prevent the flood when the software decides to rebel against you.

[KennyBlanken]

You can also use a float sensor and relay to control the pump, and use ESPhome for monitoring only.

[johnz]

That’s what I’m thinking I’ll do if/when the sensor fails. Or for v2.

[johnz]

My thoughts exactly on using ESPHome.

My familiarity with float switches is limited to boats. Any you would recommend for this application?

[invalidator]

Something like this: https://www.amazon.com/dp/B007CZ6PD2

I just noticed that you're using a mains-powered pump, so don't splice its wires directly. Instead, insert the float switch on one of the wires between the QT Py and the relay.

[sokoloff]

A condensate safety drain switch is appropriate here.

Something like this: https://www.supplyhouse.com/Beckett-Pumps-1502UR-Float-Safet...

or

https://www.supplyhouse.com/Little-Giant-599124-ACS-3-Auxili...

[johnz]

Perfect. Thank you