What Can You Do When New Controller Appeared 04 and 019First appeared 04, then appeared 019:04 is a low temperature warning. First please check the entire oil path of heater whether in which parts of the oil leaking. For example, Oil pump, tubing, diesel filter and other oil pipe connections,  check whether there is oil leakage.If the oil path is normal, please check the combustion chamber and the turbine. When the heater does not completely stop working then you directly cut off the power, the heater without cooling, the combustion chamber will be burnt, the turbine at high temperature deformation.If there is no direct disconnection of power, check whether the temperature of aluminum shell is normal, because when it is warm or hot, the heater does not work properly.If step 1.2.3.have not occurred, long press the power button for 5 seconds, the oil discharge machine then shut down after the completion of the re-start testing.If the fourth step still can not make the heater, check the sensor.Still still appear 019, may be the oil pump out of the oil is too much, please contact the manufacturer.