What is this rod for?

Hint 1 of 9:

It's too heavy to take out of the room, so you know it must be used with
in the room.

Hint 2 of 9:

The only thing you can use it on is the fireplace.

Hint 3 of 9:

Put the rod on the hearth.

Hint 4 of 9:

Look at the small metal disks on the sides of the fireplace.

Hint 5 of 9:

The rod isn't long enough to reach those contacts.

Hint 6 of 9:

You need to make the rod longer.

Hint 7 of 9:

Metal expands when heated.

Hint 8 of 9:

And this is a fireplace.  How convenient!

Hint 9 of 9:

You need to start a fire.