The air temperature fluctuates up and down during roasting
A guide if you’re experiencing fluctuating issues with the temperature graph during roasting.
Issue:
The air temperature moves up and down instead of following the target, shown in the image on the right. The reason behind this is the resettable fuse on the heating element.
This fuse will turn off the heating element if the heat applied is too high. When the temperature has been lowered, the heating element will be turned on again. Hence the fluctuating graph.
The reasons behind this could be:
The machine is not getting enough airflow. The fan related to the machine’s cooling is called the chassis fan/cooling fan (nr. 11 in the image below) and is located on the back plate of the roaster behind a mesh gritter. This gritter and the fan must be cleaned regularly so that air can circulate properly through the roaster.
The setting for the heating fan is too low. We recommend keeping it at 3400 RPM, but if you experience problems with the heating element, you can try increasing it to 3500 or 3600 RPM. To change the setting for the heater fan, you must enter the service menu. In the menu, you can adjust the fan under Settings.
3) The fuse on the heating element itself is damaged/faulty. The solution is to change the heating element. If you’re having repeated problems with your heating element, please read through this post on heating elements and their lifetime.