The side fan is designed to work and cool off the heatsink once it's power on. If not, it will cause the nozzle clog problem.
If you meet this problem, please email firstname.lastname@example.org to describe the problem and we will send you a replacement fan part as soon as possible.
Or you can order a fan in the local store and replace it. The spec of the fan is:
Size: 30x30x10 mm
Power: 12V 0.1A