Seasonal maintenance servicing is essential to ensure your evaporative air cooler operates efficiently for many years. We suggest that any maintenance or checks be carried out by an authorized Seeley International Evaporative Cooler dealer/technicians or properly trained maintenance responsible/technicians. We require that the maintenance service checklist in the evaporative cooler Owner’s Manual, be followed after the first year. Seasonal Maintenance services must be performed before and after the summer season. For evaporative coolers working for more than 12 hours per day all-year-around, it is necessary to follow the instructions described in the evaporative cooler Owner’s Manual. Of course the frequency of the cleaning depends on the quality of the water used and on the conditions of the environment.