No matter what type of heating, ventilation, and air conditioning (HVAC) unit you have, you should schedule maintenance and cleaning once a year. The ideal situation is to have the heating unit serviced in the fall and the cooling unit checked in the spring. If you own oil-fired equipment, it should be inspected annually at the beginning of each heating season.

Regular HVAC service is a necessity because every year that you own an air conditioner or heater, it becomes less efficient. Several factors contribute to this decline, including dirty vents, a decrease in fluids, and degrading parts such as the condenser coil. By scheduling regular maintenance, you can reduce the effects these have on the system.

When a technician checks your HVAC system, they will inspect the air conditioner or heating unit, including the internal and external components, as well as the connectors. They might also check your thermostat and look at your vents and ducts to make sure they're clear of dust and debris. 

If you can't remember the last time you had your HVAC system cleaned, make sure you reach out to an HVAC service technician and schedule an appointment. You don't want temperatures to change drastically and have your system not ready to keep you warm or cool. Scheduling regular maintenance for your system can help minimize the chance of this happening while maximizing the system's reliability.

Sources: Hannabery.com, Shrivermechanical.com, Experthomereport.com