Heating, ventilation, and air conditioning systems (HVAC) are an essential part of your home. In homes that use a single HVAC system to heat and cool the home, service for this system is critical, and failures or breakdowns are often a result of not taking the time to check the system over once or twice a year.
The time between service calls for your HVAC unit can vary by the type of unit and the amount of use it gets. If you used the system every day, parts can wear fast, but there are also parts like rubber belts in the system that can dry rot or have damage occur when the system is sitting unused.
For most systems, servicing the unit once a year is a minimum interval, but twice a year is better if you can. Spring service will get the unit ready for cooling, and fall service will bet the heating portion of the HVAC prepared for winter. The technician working on your HVAC may look at many of the same items during both service calls; there are some specific things they will check for heating or cooling purposes.
The portion of the HVAC unit that is outside your home has most of the mechanical and electronic parts inside the housing. The technician will remove the cover from that unit and clean the fan, check the belts, and all the wiring inside. Sometimes small animals will make nests inside the unit outside because it is warm and dry inside, so checking for and removing little critters or nests is essential.
The tech will replace belts and other parts that are worn or have damage to them, then replace the cover. It is vital to keep bushes and trees from growing around the outside portion of the unit to keep it the air flowing around the unit and so that the tech can easily access the system if needed.
The portion of the HVAC system that is inside your home often holds the fan that moves air through the air ducts, and the controllers for the thermostat. The plenum where the air comes in should have a filter on it to reduce the dust and dirt coming into the home; this filter needs changing every few months, and the tech can show you how to do that. Go to a website like http://www.coeheatcool.com to see how a tech can help you.
The technician will check the mechanical parts inside and check the fan to ensure it is working as well. The entire service call will not take too long, and once the tech is done, they can tell you if there are any areas of concern that you should address soon.