I would think that any pot which caused the "eruption" you describe is a dangerous item waiting for an accident to happen. Even tho you love them, you should return them and get pots which boil water correctly. Obviously they were not designed properly, give 'em back!

No need to return the pots.

Essentially what is happening is that there's no place, no imperfection, in the pot on which bubbles can form. With no bubbles forming, the water's surface tension keeps the heat in, and the water superheats.

When you put something in the water, you break the surface tension, and you get explosive boiling.

Are the pots stainless steel or non-stick?

If stainless, simply give them a scrubbing along the insides with something that will rough up the surface, Comet cleanser usually works.

Another way, if you don't want to mess up the look of the pots, is to put a wooden spoon in the pot as you're boiling our water. The spoon gives a great place for bubbles to form.

A tiny sprinkle of salt will fix the exploding water problem in both pots and microwaves.