Hall County Fire Services responded to a report of smoke at Chestatee High School on Sardis Road late Thursday morning.
Capt. Zachary Brackett said crews were called to the scene at 11:40 a.m. for what was thought to be a commercial fire at the school.
"Arriving units found that the school had been evacuated and a blower motor on an HVAC unit had produced the smoke," Brackett said in an email.
Brackett said the power to that particular unit was isolated.
Students have returned to class for the day.
