Ive been growing for a couple of years now and keep having the same problem. Ive tried 3 different timers so far and even used my mates that works for him but at my house after a week or two the timer sticks on and I have to reset it. I dont know if its an electrical surge or something but its doing my head in and causing me to loose crops if I dont catch them when stuck. Does anyone have any idea what it could be or had the same problem maybe, I even tried a mechanical timer and that stuck as well. Its driving me mad, any ideas welcome,,,thanks Andy