Clean the cooking grate

Brush it hot, deep clean it cold

The manual, and Weber UK's cleaning page for the deep clean.

1. Preheat with the lid closed for 10 to 15 minutes.
2. Scrub the hot grate with a stainless-steel bristle brush.
3. Check the grate and the brush for loose bristles. Replace the brush if you find any.
4. Oil the food, not the grate.
5. For a deep clean, cold: spray Weber Q and grate cleaner, wait 30 seconds, brush, then wipe with a wet sponge (Weber UK).
6. Lift out the centre insert and clean it the same way.