Rheem Heating & Cooling generally recommends changing air filters every one to three months, depending on several factors. For example, if you have pets, live in a dusty area, or use your HVAC system frequently, you may find that changing the filter every month is beneficial. Conversely, if you have a high-quality filter and do not use your system as often, you might extend the interval to three months. It is also a good practice to check the filters monthly and replace them as needed, especially if they appear dirty or clogged. Regularly changing your air filters contributes to better indoor air quality and enhances the efficiency of your heating and cooling system. For specific recommendations tailored to your model, you may want to consult Rheem's official resources or product documentation available on their website.