The answer to 'how often to replace air handler' is that the air handler in your HVAC system typically needs to be replaced every 10-15 years, depending on usage and maintenance. The air handler is the indoor unit that circulates air through your home, and it contains the blower fan, coils, and other components that are essential for proper airflow and climate control.
Regular maintenance and cleaning can help extend the lifespan of your air handler, but eventually the components will wear out and need to be replaced. Signs that it's time to replace your air handler include increased energy bills, uneven heating/cooling, and excessive noise or vibration from the unit. If your air handler is over 10 years old, it's a good idea to have it inspected by a professional HVAC technician to assess its condition and determine if replacement is necessary.