What is this button?

[Riderprider]

Hello, I bought my Wildcat 29BHS and had it delivered, so I didnt get much of a walk through with the dealer. I can't figure out what this switch does, it is near the fridge, and has a setting of Auto or Low. Also, my control panel has a level indicator for Galley. I'm assuming I only have one tank as this always reads empty. Is that correct?

Thanks in advance

[Bayouownbeer]

Could be for gray and black water tank heaters. Which keeps them from freezing in the winter