It may be a silly thing to ask, but boiling water is one of the most common cooking processes in a kitchen.
Did you know, adding salt to water actually makes the water boiler slightly slower than if you had not? The point of this is to get an even boil.
At higher elevations water boils at a higher temperature. Put a lid on it!
After your pot reaches the boiling point, turn down the heat! This will keep your liquid from boiling away fast.