Since we had to turn the furnace on I've noticed a faint beeping sound coming from somewhere within the furnace. It beeps about every 2-3 minutes or so. The furnace is operating properly, no problems with the thermostat, no problems with it shutting off, or anything. As far as I can tell, everything is working fine. The status light on the front of the unit is showing "normal". Also, the beeping only occurs when it is actively blowing warm air. I've thought about maybe it's the motor just squeaking, but it's a no-kidding beeping sound. Any thoughts? And no, it's not an alert telling me to change the filter. I appreciate any help. Furnace is about 5 years old.