Yes! Residue from minerals and coffee oils can accumulate inside the machine over time. So even if it doesn’t affect the taste of your brew, the residue can cause clogging and put unnecessary strain on the internal parts of the machine.
Studies have also found coffee makers to be one of the top 5 areas in the home to harbor contaminants. So a dirty machine is more than just a matter of coffee taste or brewing performance, but also a safety concern.