John after all your years with a Disco and you don't know that, don't feel bad I forget and have to practice pushing button to find the right ones.
I know you have to push 2 outer buttons at the same time. If I get a chance I'll run out to my truck and re-educate myself so I can tell you.
Been doing that lots lately: to change it from C to F, press and hold the recirculation button and then the power button- at the same time holding them both down for a few seconds until you hear it beep.
Mike, I can't tell you how many of the stupid little things I forget how to do on these things. I can't tell you the last time I had to change the climate control readings. I might have done it once or twice over the years.