By Monday morning it was pretty clear we weren't getting any heat. lonelydumptruck investigated and discovered he had put the filter in upside down.
He was worried he'd borked our furnace, but when the guy came to look at it on Wednesday it was (luckiky?) that a part had failed.
Wednesday was ALL teh adulting! So we were able to discover our tax return just about covers the cost of fixing the furnace. That is big, though, since I don't think we have gotten money back yet this century.
Plus, our house was warm by the time lilbluegnomeo and Mike D came over for tacos and Alhambra.