We have a separate Jenn-Air 36" telescoping downdraft vent (#HV363) installed behind a 36" 5-burner Jenn-Air gas cooktop. The problem is with the downdraft. Specifically, after several months of working perfectly the downdraft vent has begun intermittently acting up. After you press the "on" button on top of the cover the telescoping unit should rise and remain in the raised position and the vent fan come on. Instead the unit rises to the raised position and then immediately reverses and lowers to the down position. But it doesn't stop there: the unit then continues to cycle uninterrupted between raising and lowering for several minutes until -- presumably when a temperature sensor acts to prevent the motor from overheating -- it simply stops. After 20 minutes or so the motor comes back on and the cycling resumes. We have to go into the cabinet containing the downdraft unit and unplug the vent from the outlet to stop the problem. Sometime later the unit is plugged back in and in most, but not all, cases the unit shuts off the next time it is in the lowered position. On a few occasions the unit simply resumes cycling between raising and lowering, so we unplug it again and plug it back in later. My sense is that there must ne a sensor switch somewhere that isn't being activated (in either the raised or lowered positions) that permits the unit to cycle. We're quite skilled at DIY repair of equipment and appliances and would appreciate any advice you might be able to provide. We really like this downdraft vent - when it decides to work properly - and look forward to hearing from you. Thanks!