Performed semi annual maintenance and American standard gas furnace with straight Ac, check Tstat and wiring ok, filter recently changed, check heat exchanger ok , check inducer motor ,gas valve and pressure switch ok , check flame rectification system,pull and clean flame sensor, change (7.5 mf ) run capacitor , check blower motor and wheel assembly clean, bumb condensor, check standing pressures ok , system operational Supply temp # 136 Return temp # 76 Temp rise # 60 degrees