Just a note for this coming week of frigid temps, furnaces are designed to be efficient for the majority of the year. We size furnaces to heat your home to 72-75° on 0° day. That way it’s not oversized for majority of the winter.
So, when it’s -15°, your furnace or heat pump is gonna be RUNNING!
And may not keep up. It probably isn’t broken. But it should keep it pretty warm still.
You may not want to set it back between now and then. And if you have a closed wood fireplace stove, give your furnace some help.
You may also want to over heat the house before the drop.
Be warm, be safe.