The answer to 'how often to replace preventive maintenance' is that HVAC systems typically require preventive maintenance once or twice a year, depending on factors like the age of the system, usage, and local climate conditions. Regular maintenance helps ensure the system is running efficiently and can extend its lifespan.
Most HVAC manufacturers recommend having a professional technician inspect and service the system at least once a year, typically before the peak heating or cooling season. This allows them to identify and address any issues before they become major problems. Some homeowners opt for bi-annual maintenance, having the system serviced in both spring and fall to prepare for the changing seasons.