Ok it was a little chilly this am so I fired the new Rheem 2 stage. It was 65 in the house so I put the stat at 67 all went well and I assumed it was in low fire stage ??

I then just for the heck of it bumped it to 75 degs, I heard the stat click and then flashing in the stat was the word " Aux" is this mean it went to hi fire stage ??

Its hard to tell listening to it but the fan may have been running faster ??