Diagnosis
Flare-up caused by excessive grease accumulation in the drip tray or on the heat deflector.
How to Fix It
DO NOT OPEN THE LID. Turn the grill off using the power button. Unplug it from the wall. Let the fire burn out inside the sealed chamber, which will suffocate it. Have a fire extinguisher ready. After complete cool-down, remove and clean the drip tray, grease bucket, and heat deflector thoroughly.
If That Didn't Work
If flames are escaping seals, use a Class B dry chemical fire extinguisher through the top vent. Do not pour water on a grease fire.
Heads Up
This is a maintenance failure. Clean the grease management system after every 5 hours of cook time, especially with high-fat foods like burgers or chicken thighs. Never skip this.