The phase thing is simple. I doubt what you are being told is correct, if anyone who understood transformers stood and looked at you nearest one they could figure it out,
However you have 120 v from the one side of the fuse or breaker panel to the middle (neutral).

If you go from one side to the other not using the neutral you get 240 v.

There are 3 wires coming into the house. One is the neutral, the other are the phases.

There should be roughly half of the breakers or fuses on each side, the stove for one straddles the two.

When one phase goes out, either a transformer or feed wire failure, only 1/2 the panel is live. The stove crosses over. You turn on the stove and you feed, based on the variable nature of the switch, power across to the dead side. It does however flow back out towards the break to a degree, but through your dead side, so if you have lights on it will act as a dimmer switch.

I've had this happen twice in recent years and when I call up and tell them a phase is out they usually get the attitude wtf you know about that old man? Nice.

If I'm maybe wrong I usually don't open my mouth and prove it is all.

Or I tell you the story about one time...never mind.

John Conley
Musica est vita