Upon arrival performed heating tune up for 2 systems. Indoor motor and wheels leaking some oil. Have play in shafts. Indoor blower wheels both dirty and need cleanings. Returns are not sealed, collar to plenum is not sealed on both systems. Circuit board and electrical connections good. Dusted off electrical connections. Gas valves in working order. Filters swapped. Heat exchangers on downstairs system has a lot of heat marks, metal is getting weak. System has small returns