Customer had furnace off at disconnect switch. Resupplied power and called for cooling. Found voltage absorption system dead. Not allowing compressor or fan to operate. Presented options hn13 A-E to address fault. Customer chose option a due to wanting to sell soon. Found rust and crack in flue pipe informed customer of issue. Customer chose to let it go for time being. Preformed repairs cycled unit. Unit cycled properly and ran with 19 degree temperature drop. No further concerns