Let the stove cool down before cleaning.
Pour baking soda on the burnt water spot to cover it. Use a damp rag to scrub the baking soda into the stain. Rinse with water. If the burnt spot lessened, repeat the baking soda treatment until you've cleaned the whole spot. If you see no change, proceed to the method in the next step.
Use a commercial stove top cleaner if the baking soda doesn't work. Apply the product to the stain and allow it to penetrate for the recommended wait time on your product's instructions. Scrub the stained area with a sponge or rag and then rinse.
Wipe the stove dry with a paper towel to restore the cooktop's shine.