I think you'd want to know right away that you have a CO leak. You can call in an emergency utilities guy to drain the pipes - the internal insulated ones won't

I think you'd want to know right away that you have a CO leak. You can call in an emergency utilities guy to drain the pipes - the internal insulated ones won't burst within a couple hours. And as the other commenter says, you can almost certainly restart the furnace or cancel this action.