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. Furnace is in great working order at this time. Tech made two notes. 1- the humidifier pad is calcified and leaking into the furnace. The pad should be replaced to prevent any damage. 2- the ducts, blower assembly and secondary heat exchanger are very very dirty. This is causing the furnace to lock out some times on high limit. Client is in the middle of remodelling the home. And asked for a duct cleaning quote. Tech has quoted work. Client will discuss with her husband and schedule duct cleaning after the remodelling has been done