Recently we had our 8 year old furnace cleaned, the general type 'tune-up'. Since then, while the blower motor is operating, there's a high-pitched whine. Any advice? My family thinks I'm worrying unnecessarily.

If you know how you might check to be sure the blower has not sucked up a paper or something out of the system. You have to turn off power and take off blower door to do this.