Things You'll Need
Day & Night manufactures a broad product line of residential gas furnaces. The company recommends periodic replacement of the air filter to ensure the furnace operates properly. Homeowners can replace the filters easily and without the need for tools.
Access the air circulation chamber of the furnace by opening the upper housing door to expose the furnace filter. This door is on the front of the furnace and is labeled as the filter access.
Extract the existing furnace filter, taking care to note the direction of the airflow arrows printed on the filter's frame. Day & Night furnace models have two styles of filter brackets. With one style, small metal levers secure the furnace filter, and you twist the levers to the side to remove the filter. In other models, the filter's frame fits into side channels from the top; you release the filter by pulling it upward out of the channels.
Install the new furnace filter, making sure to align the airflow arrows printed on the filter's frame to match the direction noted on the old filter.
Close the door to the air circulation chamber.
Record the installation date on the new filter’s frame to use as a reference in your replacement and service scheduling.