Diagnosis
Excessive flare-ups are caused by grease ignition. The primary source is an overfull grease management system or food debris on the flavorizer bars and burners.
How to Fix It
Empty and clean the grease tray and the removable drip pan underneath it. Next, remove the cooking grates and flavorizer bars. Scrape all carbonized grease and debris from the bars. Clean the burner tubes to ensure ports are not clogged, causing improper flame that licks accumulated grease. Reassemble. For your next cook, preheat on HIGH for 10-15 minutes with the lid closed to burn off residual grease.
If That Didn't Work
Your cooking technique may be contributing. Trim excess fat from meats. Avoid letting large amounts of marinade or sauce drip directly onto the flavorizer bars. Use indirect heat zones for fatty foods.
Heads Up
Never leave the grill unattended during a flare-up. Do not use water to extinguish a grease fire in the grill. Turn all burners to OFF and close the lid to smother the flames.