Just last week, the central air conditioning fan inside my home started making a constant loud noise. What could be causing it? Could the fan be hitting something?
There are several possible causes for a noisy forced air system. When a fan's bearings begin to wear out, it's generally characterized by a lot of vibration and racket. There's also the possibility the fan is baked with dirt or dust, which is forcing it out of balance, again resulting in noise. There's also a chance something inside the compartment has gotten loose and is rubbing against those fan blades. To get to the bottom of the problem, have the fan thoroughly evaluated by a HVAC tech. While that tech is in your home, make sure he or she also services your entire system for the upcoming season – whether it's summer coming up, or winter.