I have 2 6101 powerheads on a 7095 controller for 2 plus years now. One of them works fine. The other has become non-responsive to the controller even if I switch it to another outlet on the controller. It is constantly on. If I hit the feed button it stays on. I can regulate the flow by adjusting the little dial on the blue box, but the only way to turn it off is to unplug the transformer. What's the problem and solution? I'm sure I'll need to replace something.... Thanks!!