The house has a gas boiler for heat. The startup sequence requires the blower motor to come up to speed before the burner lights to generate steam, and therefore, heat.
Sometimes the blower motor sticks and will not start to spin up. It will just buzz and heat up. This evening was one of those times. I woke up and could tell something was off. The upstairs rooms I use don't have radiators, but I could tell it was colder than usual. Went downstairs to the main floor, and yep, the temp was 59F. The motor had stuck again. I turned off the heat, went to the basement to give the motor fan vanes a little nudge, sprayed a cooling gust of duster air inside the motor casing, and turned it back on. Heat has returned.
This is becoming a more reoccurring problem this winter. Not going to spend money to fix, because I can't be sure I'll still be in the house another month.