Broken/Loose Heatbreak

Image from Reddit

The heatbreak is the part of the hotend that controls the transfers the heat between the heatblock and the heatsink. Details on the heatbreak are covered in our hardware glossary here:

Hotend & Nozzle

There are many varieties of hotend designs, but a number of them use the heatbreak not only to control thermal transfer, but also as a structural element to hold the heatblock (a good example is the E3D V6). As a result, the heatbreak is prone to being bent/broken if the heatblock is not properly handled. This happens frequently during nozzle swaps.

To replace the heatbreak, heatblock and/or heatsink on the MK3S, you can check out this article:

Prusa KnowledgebasePrusa Knowledgebase

Replacing heatbreak, heatsink and/or heaterblock on the MK3S