Preheat your gas grill with the lid closed and all burners on high for 15 minutes

Yes, you want all burners on high with the lid closed for 10–15 minutes. No shortcuts.

The goal of preheating isn’t just to get the grates hot—it’s to stabilize the entire cooking chamber. With the lid down, the heat radiates and reflects off the lid and the back wall, smoothing out hot spots. If you leave the lid open, you lose that heat soaking, and the grates near the front will stay cooler than the back.

After 15 minutes, brush the grates clean (the burnt-on stuff comes off easier when hot), then adjust burners to your cooking setup. For even cooking across the whole grate, you can keep all burners on medium or high, but most people want a cool zone for indirect heat. That’s a separate step—don’t skip the preheat just because you plan to turn one burner off later.

A properly preheated grill also stops food from sticking and gives you those clean grill marks. Cold grates rip the skin off chicken thighs.

Skipping a proper preheat is why your burgers look like a map of the world.