Heating maintenance in Roswell. Tested operation of 2 furnaces. Discovered upstairs system with dirty blower wheel which causes it to be unbalanced putting extra stress on blower wheel and affecting efficiency up to 20%. Discovered downstairs system operating with a weak ignition system, weak blower motor controller, dirty blower wheel, and exhaust flue piping leaking. Both systems heating at this time. Due to age and condition of downstairs system replacement is highly recommended. Homeowner waiting on basement system to die before doing anything