Quote Originally Posted by Tfpets View Post
Those zillas have a habit of sticking on. They have a cheap relay inside and the contacts will weld themselves together. I never had the problem right out of the box but they all eventually did it. It could be a different problem but I have learned to not trust (or use) them anymore. I would return that one and look for a hydrofarm unit, either online or at a hydroponics store. They are in the same price range. You could also go for a herpstat or higher end one in the $100+ price range.

Edit: You might be able to get that one working again by smacking it or hitting it on a hard surface. Usually that will break the contacts loose.
I'm getting a new one soon, I was just planning to use this one for a few days (thought it would be okay for that long) until I could get a new one.