After eight years, the igniter on my Genesis 300 series would occasionally fail. I ordered the igniter kit along with a new knob and now it's working like it did when I first bought it.
I have had my Genesis since 2008. Then, a major re build in 2005 because Weber had the parts I needed, at a very reasonable price, and were extraordinarily helpful via phone. Now, I've replaced the entire ignition system which was easy! The parts I needed were easy to find on their website, the instructions were clear. Total installation time, 20 minutes! If and when I need a new grill, it will be a Weber!