We recently had a problem with our furnace. It was really clogged up and filthy. We just bought this house, so this is what was here all along. The debris inside blocked airflow, forcing the furnace to run harder and endlessly to reach control unit settings. This uses more energy, raises bills and more. There’s also the fear of the furnace overheating and a potential threat from carbon monoxide. Even at peak capacity, I doubted the furnace would be easily energy efficient. I hired a licensed Heating, Ventilation, plus A/C supplier to inspect the furnace, including the duct system, and give a recommendation. Fortunately, the ductwork was in good enough condition to keep. We were able to get by with having the ducts professionally cleaned and sealed. This process was fairly expensive, but was handled abruptly with no injure to the home. Unfortunately, the furnace was beyond saving. The supplier discovered a minor crack in the heat exchanger. Since the heat exchanger prevents the introduction of combustion byproducts, such as carbon monoxide, it’s harshly crucial. The cost of a replacement heat exchanger is more than a whole current furnace. Although the current furnace was a massive expense, I felt better knowing both of us were relying on a safe, energy efficient piece of equipment. The new furnace keeps us comfortable, even on the coldest of days.