How do I get water spots off of stainless steel?
There are several ways to clean stainless steel that should work on your tea kettle.
Maybe one of them will work for you:
1. Gather a one medium size towel and one hand towel; lay by sink. Place tea kettle in sink; heat a pot of plain water to very hot and pour hot water over tea kettle.
Immediately dry with larger towel and finish off with smaller towel. This will many times remove spots and leave surface very shiny.
2. Add enough white vinegar to three tablespoons of baking soda to form a thick paste. Apply it with a soft rag or sponge and scrub until the stains disappear, then wipe the kettle with a damp cloth. Barkeepers Friend can be used instead as it does not leave scratch marks either.
3. Place a small amount of mineral oil on a cloth and wipe surface. Use warm soap and water to remove mineral oil but dry immediately with a soft cloth.
4. I have heard of using Windex but I cannot vouch for this.
The stain is not really from the water. It is from the minerals in the water. Lemon juice or vinegar, both mild acids should react with the minerals to loosen them from the stainless steel so you can rinse them away. You could also use any of the products for mineral build up in the bathroom like CLR and I agree that Barkeepers Friend will also work.
Barkeeper's Friend is excellent for this.
Magic eraser works wonders!