I had the issue of them stopping working when we had a power outage for a few days and I had to move all my racks to my parents house (they had power...and were thrilled to take in my snakes..). Turned out the clamped metal thing came a little loose. It was still holding on there, but was loose enough that it broke the connection. I ended up re-splicing the wire and connecting a whole new metal thing, then reclamping it in a different spot on the flexwatt. It fixed the problem, sorry I'm not very good with technical terms of the parts, but I'm hoping you know what I'm talking about lol.