A couple of days ago, I was laying in bed and I heard a strange noise coming from the ductwork. At first I thought it was a mouse, but it sounded more like a whining sound. I probably would not have noticed the strange sound, but I was awake in the middle of the night. I couldn’t sleep because I had a headache. The same strange sound continued for 3 days in a row, so I decided to call the HVAC service provider this morning. I was a little concerned that the issue might be severe. I told the service provider that there was a strange sound coming from the ductwork. It was time for a tune-up anyways, and I thought I could get everything done at the same time. The person on the phone agreed that a tune-up was a good idea if I was hearing a strange sound coming from the HVAC system. After the HVAC service provider checked my ductwork this morning, I found out exactly what was causing the noise. One of the pieces of ductwork was no longer connected to the next. There was a 2 inch space and it was creating a whistling sound every time air passed through the ductwork. It didn’t cost a lot of money to repair the ductwork issue, and I had the rest of the system cleaned and serviced at the same time. The work is under warranty as well, so I can call the HVAC provider if I have any other additional problems with the ductwork in the future.