Let me tell ya folks, if you are thinking of going Alkin W31, I highly recommend the auto features as an upgrade.
The darn thing did scare the bejeebers out of me the first time that I ran it, as it automatically purges when the auto shut off trips. I was not expecting it, and it gave me a start.
Even on a short run, once the auto shut off trips the auto drain purges at the same time regardless of run time.
I am now relegated to merely watching a gauge for the correct pressure to open my tank valve for a fill and the Alkin does everything else.
Well, I do have to push the start button and it is kind of low down close to the floor, so that is a sort of negative. But then I realized that I could just sit on my roll a round shop stool and I did not have to bend as far and I was happy again!