Check your filter each month. A dirty filter starves your system of air and causes excessive wear on your air condition, furnace or heat pump. Replace you filter when necessary, or clean it if you have a reusable type of filter. If it's reusable, make sure it is dry before you re-install it.
By installing your filter backwards, air will have a harder time flowing through the filter and your air handler will have to work harder to make up for the loss of airflow. ... That arrow must always face toward the furnace and away from the return duct that carries the air in need of heating or cooling.
On your new filter, find the arrow that indicates the proper air flow direction. This tends to confuse everyone more than anything else. That arrow must always face toward the furnace and away from the return duct that carries the air in need of heating or cooling.
Make sure your outdoor condensing unit is level and stays in a level position. If the support for your outdoor unit shifts or settles, relevel it to make sure moisture drains properly out from under the unit.
Keep your outdoor condensing unit free of debris. If you keep grass clippings, leaves, shrubbery and debris away from your outdoor unit, it should only require minimal care. Check the base pan (under the unit) and remove debris to help the unit drain properly.