You need to have a heating, ventilation, and air-conditioning specialist on the case as soon as you determine that your furnace is not up to par. The professional can then analyze the entire system for appropriate solutions, including furnace repair in Madison, WI.
Stephens says age and annualized fuel utilization efficiency (AFUE) levels are clues as to whether the furnace is still in working condition. The production labels on the machine can be crosschecked with the manufacturer and if it is at least fifteen years old, your contractor may recommend a replacement as soon as possible. Furnaces of that vintage are likely to have AFUE grades of no more than 76%.