I put super hot steaming tap water in up to the 6 cup mark and it took 6 minutes to boil, still no whistle

This took 10 minutes to boil using cold water from the tap and filled to about 8 cups and the whistle is almost nonexistent

Between the medium heat and the trivet, it takes 30 minutes for water to boil

Excellent for tea or coffee brewing the boiling takes just a few minutes.

My old wide-bottomed stainless steel kettle (which lost its whistle) took 6 minutes to boil 6 cups of water on my gas stove and this new glass kettle took 16 minutes to boil the same amount of water.