Tech came out to perform heating maintenance inspection. Tech tested the heating system: checked gas pressure, temperature, exhaust fan amperage test, blower motor amperage test, flame rectification sensor test, exhaust fan vacuum test and a combustion analysis. Tech found the basement. Furnace is working well no issues at this time. However, the main floor furnace has an issue with the gas valve. It is a non-adjustable gas valve and the maximum gas pressure rated by the manufacturer is 3.5 inches of water column. Gas valve is reading 3.76 and sometimes as high as 3.9 inches of water column. Tech informed clients and quoted to replace the gas valve. Client will hold off for now as the furnace is working. Tech replaced both furnace filter filters and checked humidifier. Humidifier pad is still good and does not need to be replaced. However, both filters have been in since July tech replaced both filters that client had on site. Client thanked us for coming out today.