Systems and methods for pre-ignition moisture removal in heating appliances are provided. The heating appliance may be configured, prior to initiating a combustion process using a combustion system of the heating appliance, to determine whether a flame sensing unit is producing false positive outputs. In some instances, such false positive outputs may be caused by moisture within the combustion cabinet of the heating appliance. To attempt to eliminate any false positive outputs, the heating appliance may perform ana action to expel the moisture from the combustion cabinet. For example, an inducer may be activated to expel the moisture using airflow. This ensures that the flame sensing unit is producing accurate data before the combustion process is initiated.