OK, I think I’ve found a solution—at least a temporary one. It’s the connection between the square end of the brush and the part of the vacuum that makes it rotate. Apparently this can wear and cause the brush to rattle when rotating.
The solution is to take a something like plumber’s tape and wrap the square end to create a tighter connection. While it hasn’t solved the problem completely, it is significantly better.
If you’ve tried the following and nothing has worked, this could be a solution:
- If you’ve cleaned the brush
- If the noise only occurs on hard surfaces
- If there is no noise when running the Eufy without a brush.
There are more comments about the issue in this thread on Eufy’s support forums.