Product review (4 stars): Looks like the plastic inside the knob loosens up and no ...
The Cooktop has served us well for 5 months, then as given by one other reviewer, a knob failed to properly engage the spindle on the gas valve. The vendor (Extreme Video) got a replacement knob. Now, after another 3 months, a second knob has the same problem. Looks like the plastic inside the knob loosens up and no longer is tight enough. I see a tiny crack in the plastic. Yikes. Hope the vendor responds to my email from 5 days ago. Still waiting.  Otherwise, the cooktop is great.