What happens if the water level evaporates to below the minimum water level indicated on the precision cooker?
It would be bad. Not total protonic reversal bad, but bad.
(could burn out the heating coil)
The anova has a sensor and will shut off and make a very loud beep if it cannot detect any water.
There are a number of threads on this and creative ways people have come up with to slow evaporation.
I just cover my pot with tin foil/saran wrap and a towel. I usually don’t do cooks longer than a couple hours but I’ve never had a evaporation issue.
If you’ve connected your phone to your Precision Cooker through the Anova Culinary App, you’ll also get a notification to alert you that the water is low, but going below minimum is easily avoidable with a few insulation tricks. Here’s a few good pointers on insulation and vessels if you want to get more info: https://anovaculinary.com/sous-vide-container-guide/