Ballu air conditioner error code Ballu Air Conditioner Error Code Ballu air conditioner error code,MFS2 series E1, E2, E3, E4 – Temperature sensor (internal or external unit, condenser temperature, evaporator temperature) is small or broken. E6 – External unit safety tripped E8 – Closed Electrostatic Filter P4 – Error on Evaporator Sensor, Very Low /