Grill isn't heating or cooking properly
Gas grills generally provide fairly even heat, but it is normal for there to be a slight temperature variance in different areas of the grill. But, if you notice that part of your grill is either not heating or over-heating, there’s something wrong.
Gas grill burners have several ports along the sides where the gas flows through to produce the flame. When grease and food drippings fall down the grates, the drippings can clog the ports so the gas can’t flow properly. You can try cleaning the burner by using a grill brush to remove the drippings from the inside and outside of the burners. If the burners are too clogged, you may need to replace the burners.
Greasy Flame Tamers
Flame tamers cover the burners on a gas grill. They protect the grill burners from the bulk of grease and food drippings; they also infuse your food with flavor as the drippings heat up and create smoke. When the buildup is too thick, the flame tamers can cause flare-ups and uneven cooking. You can clean the flame tamers with a good brush, but if the buildup to too thick, you should replace the flame tamers. (Flame tamers are also known as vaporizer bars, heat shields, or heat diffusers.)
Rusty Heat Tents
Heat tents (also known as flame tamers) work best when they are clean. Those that are rusted can cause flare-ups and uneven heat distribution. You can remove light, surface rust. But if the heat tents have moderate to thick rust or some of the material is rusted away, you should go ahead and replace them.
If you’re experiencing uneven heat on your grill, try cleaning your grill. All else fails, you may need to replace the parts to ensure that your grill is working properly.