I was called to a home to perform furnace maintenance on a POF gas valve and duct cleaning. The POF gas valve was not working properly, and the duct cleaning was necessary to improve the air quality in the home. I inspected the gas valve and found that it was not working correctly due to a faulty valve seat. I replaced the valve seat and tested the gas valve to ensure it was working properly. I also cleaned the ducts using a powerful vacuum cleaner to remove any dirt, dust, and debris that had accumulated over time. The ducts were then sealed with mastic to prevent any future buildup. The homeowner was very satisfied with the work I performed and expressed her gratitude for the improvement in the air quality in her home.