Most heating systems will need to be replaced when they are around 15-20 years old. If you have a heating system of this age, it may be time to replace it. Other signs of a failing heating system include.Troubles warming your home. Slow to turn on. Low airflow Bad or strange odors. Loud, banging noises. Larger electricity bills.If you notice any of these signs, it is time to contact Russell’s. We will inspect your heating system and give you service recommendations.