ac, I had that happen to us early on. My practice is now to turn the dial past the 6 minute point, then manually turn it back to the 3 minute setting and be sure to listen for the ticking. Sometimes we even have to tap on the box to get it to start ticking. Fortunately for you they are cheap enough to buy if the warranty does not cover it.
Yeah, I don't think there is any secret to getting this one to work again. Something internal has failed.
I see they are $15 at Home Depot. I put an email in to Darren at AHS to see what he says.
I might just replace it with a light switch.
ac