Testing your heat sink is a part of regular maintenance. See steps below:
* Remove the heat sink
* Place heat sink in the palm of your hand, blocking the holes on the bottom.
* Please make sure the holes are covered, or the test is inaccurate.
* Extend the stem, and try to draw air (sucking in).
* You should not be able to draw ANY air through the stem.
* Equally as important as having a tight seal is making sure there's no material build-up/reclaim in the following areas or air will not pass freely and the MV1 won't work correctly: