Try to avoid this if you can, but if you just have to take a peek, remove the steak from the grill and use the tip of a paring knife to make a cut into the center of the steak to see how things are going. Keep in mind that the steak will continue to cook as it rests after being removed from the grill. Cutting into the steak is discouraged because it will release the precious juices that help flavor and tenderize the meat.
The trick with seafood is to make sure it doesn’t stick. So coat it lightly with oil and check that the grate is clean and very hot. For fillets and whole fish, you can also try this foolproof (albeit more time-consuming) method: Place the fish on a soaked cedar plank or a lightly oiled piece of heavy-duty foil, then grill (covered), over medium indirect heat.
Inspect your burners for signs of corrosion or anything blocking the row of flame holes. Burner tubes are inviting spots for spiders to lay eggs if your grill goes unused for a while. Use a wire brush and clean them by brushing back and forth over the holes, not down the length of the tube. The wire bottle brush can clean out the inside of each tube.

Brush your grill grates after every use (inspect for wire brush bristles before cooking), and thoroughly clean them every couple of months, depending on grill usage. And twice a year, you should give your grill a thorough cleaning, which helps it cook better and last longer. The basic process is the same for gas or charcoal grills; charcoal grills just have fewer parts.

Certain practices can help discourage deposits of dirt and grease from forming in the first place. One method is to grease the grates of your hot grill with a little cooking oil right before your start cooking. In the same vein, scrubbing your grill grates with a raw onion is another tactic you can try. If you do have a grill brush without bristles, it's a good idea to scrape your hot grates both before and after grilling.
Cookout season is just a few short weeks away, and if your gas or charcoal grill is still covered with the remnants of last year's cheeseburgers and Hawaiian chicken, now's the perfect time to give it a refresh as part of your spring cleaning routine. These speedy tips from the Good Housekeeping Institute Cleaning Lab come from years of testing outdoor grills as well as the cleaners and tools you need to keep them working well (and your food tasting great).
Check the fuel lines for visible defects. If any fuel lines have unmistakable damage (like rips, holes, cracks), replace the parts immediately before your next use of the grill. Also be sure that any fuel lines have a smooth trail. You don’t want any of your fuel lines to be bent, because that will prevent the gas from flowing correctly. Check the exterior of the gas tank for any damage as well; things like dents, erosion, punctures, or any evident signs of damage. If you find areas that have obvious damage, you could potentially have a gas leak.[5]