well, the excess ice is due to either the temperature control, either bimetallic or electronic thermostat
It can also refer to the defrost control (if it has one). It has a timer, a sensor and a resistance
and there is a third one that they do not teach in the school and so if there is a gas leak, the entire pipe does not frost and if the sensors are where there is no frost they do not detect that there is already frost and it starts to produce a lot of ice