Remove any debris from the off-season. Any degreaser will do the trick, but the Crown Verity BBQ EZ Grill Cleaner is highly recommended.
If any radiants feel fragile, it's likely time for a replacement. To clean burners, remove each burner and clean them out with a bristle pipe cleaner or compressed air.
Spray the Crown Verity BBQ EZ Grill Cleaner on the grates; let it sit for 30 minutes. Rinse with a pressure washer. Soak for 30 minutes and scrub off residue with an abrasive pad.