The past couple of heating seasons, my Rheem Criterion furnace has squeaked a bit on starting early in the morning. This morning, it squealed like crazy. I believe the squeal may be coming from the draft inducer motor. What's odd is that after squealing in the morning, it's fine for the rest of the day. Sometimes I will hear a "pinging" sound when the motor stops.
I opened up the burner compartment and had a look at it. The motor rotates freely, without making a sound. I don't see any place to lubricate anything. Is there something I can try, or do I need to replace it? If I need to replace it, can I just replace the motor, or does the whole assembly need to go?