Heating maintenance Decatur. Completed heating maintenance on 2 11 year old systems. Both systems heating good. Upstairs has a concerning amount of corrosion on evap coil. No leaks detected at this time but copper is being eaten away. Both blowers are clean. Combustion and ingnition is good downstairs. Downstairs missing secondary water safety. Customer is thinking about selling home. Will wait until she decides to move on with repairs.