Restore power at the service panel and try starting the furnace again.

Perform all tasks, including opening the service panel, with one hand only.

These are easy to distinguish in the service panel.

One with a service panel in the back which, unusually, opens from the inside too.

If it does, return to the service panel and try another breaker.

Return to the service panel and turn on the power.

Sometimes this information is posted on the service panel or near it.

The only safe way to shut off power is at the service panel.

Begin at the service panel, by shutting off all power to the circuit you will be working on.

Go down to the basement to look at the electrical service panel.