Performed two system 2002 Bryant furnace maintenance. Client stated that they are very conservative do not use heat too often. When they do temperature set at about 75°. Began my maintenance and noticed multiple points of concerns. Furnaces 1. Found that both indoor blower motors are leaking oil and can cause the motor to over heat or lock up if left in this condition. 2. Both single secondary mother controls are out of range and week due to motor using more power than needed 3. Static pressure on system was at 0.75wc indicating to me that the airflow is not adequate enough and the proper specification should be at 0.5wc. This number is higher due to undersized returns vents. 4. Flame sensors are oxidized. This can cause failure with the sensor for it being able to detect that the burners are on. 5. Heat exchanger had extremely bad Heat spots. This is due to overheating and air flow restriction causing the temperature to operate at a much higher temperature than it’s designed for.