Performed annual heating maintenance loomis 14 yr old split system in attic. Found that unit is not draining correctly, gave options for what can be done. On furnace, found loose and 90 percent flue. Not sloped correctly removed it and full of water. When you replace drain pan, need to cut and responsible flue drain. Tested furnace adjusted gas pressure. And adjusted slope of furnace drain. Cleaned burners and flame sensors. Silver flex ducts ok shape. Tested system for high stage heating working well at this time