Check your filter every 30 days. If you have pets or allergies, change it that often. If not, every 60–90 days is usually sufficient.
It is the single most effective way to maintain the longevity of your system. A clogged filter restricts airflow. When airflow is restricted, your system has to run longer and harder to reach the desired temperature. This leads to: Check your filter every 30 days
If you answered "yes" to two of these, you are likely throwing money away on repairs. Investing in a new, energy-efficient unit will lower your monthly utility bill immediately. change it that often. If not