Air conditioning systems should be serviced at least once a year. Furnaces need to be serviced every one to five years, depending on the type of furnace. Experts recommend having air conditioning systems inspected in the spring.
Gas and oil furnaces should typically be inspected and serviced by a professional annually. Electric furnaces usually need to be checked every five years unless issues are present. Heat pump systems generally need to be checked and serviced every other year. Some newer furnaces require less maintenance than others, so owners should check with the manufacturer or a service professional about specific requirements for a particular model.