If people thought of their grills like they do their stove-tops, there would be fewer problems with grills wearing out. Think of it this way, after cooking something on the stove, you generally have to wipe up the spills. Every now and then, depending on how often it gets used, you should do a more thorough cleaning of your grill. This includes moving everything out of the way and wiping around and under the burners. A grill should be treated like the stove. Every time you use it, clean it.
Cooking grates are no exception to this general rule. They need to be cleaned completely after every use. This prevents food from sticking on your grill making it much easier to cook on. There are a lot of products on the market for cleaning your grate, but really any good stiff wire brush will do. Now, few people seem to know the best way to perform this little task. First of all, it is better done after you grill and not before. Once your grill has cooled down a bit but is still warm, take your brush and clean off any remaining food particles. It is much easier to clean off food particles while warmth is still present and not after they have cooled and been allowed to harden on the grate. The cleaning process can be made easier if you have a large container of degreasing solution that you can soak the grates for at least an hour and clean off the carbon with a wire brush or stainless steel wool.
The bad thing about many gas grills is that they have a setting on the knobs marked “clean”. Many people are misled into thinking that this is how you clean a grill. Like a charcoal grill, you need to clean your gas grill every time you use it. Make sure that the grates are cleaned after you grill, and brush off the sides and lid after every use. Use the clean setting to preheat your grill. Yes, it will burn up stuff that has fallen down into the grill, but it doesn't really clean it. Regularly you should lift out the cooking grate and clean off the barrier above the burners. This might be lava rock, briquettes, or some variation of metal plates. Regardless of the style, it should be cleaned to remove the cooked on grease and food particles periodically.
At least once a year you need to do a good deep clean on your grill. This requires that you take portions of it apart. First, start by turning off the gas and then scrubbing the residue off of each part and removing each part layer by layer. Once you get down to the burners, make sure you inspect them thoroughly. Removal of the burners can be tricky depending on the model, but once removed brush and ensure each burner hole is clear. If burner is clogged it will give you uneven heat and make for poor grilling. If the burner is rusted or damaged make sure you get a replacement part before reassembling. If your grill uses lava rocks or ceramic briquettes you need to make sure that these are not too heavily encrusted with cooked on foods. If they happen to be, replace them to avoid bad tasting smoke that dirty rocks can produce.
With everything out of the grill, vacuum out the debris from the bottom of the grill and then clean it completely with a degreaser solution. To ensure that you do not damage the counter surface around the grill, place towels around the the sides and back. Wipe all surfaces clean with rags, stainless steel wool, small brushes and other small tools that can reach the corner areas. Once clean, put everything back in, check to make sure that all connections are good, and then turn it on. Let the grill heat completely before you cook again to make sure that any leftover soap residue gets burned off.
For a final detailing step, use a stainless steel polish on the outside and then coat with a stainless steel grill protective spray to keep your grill looking new and clean.