Symptoms
- Motor runs but no ground coffee comes out
- Grinding sound but very slow or inconsistent output
- Grinder stalls or stops partway through a batch
- Grounds are much coarser or finer than the setting selected
Likely causes
- CommonBeans jammed in the grinding mechanismA stray bean or foreign object (like a small stone) can wedge in the burrs or blades.
- CommonOil and residue buildup coating the burrs, especially from oily dark roast beansThis buildup can reduce grinding efficiency and cause clumping over time.
- PossibleGrind size set too fine for the bean type or grinderAn extremely fine setting can overload some grinders, especially blade types.
- PossibleHopper not seated correctly, blocking bean flowA misaligned hopper can prevent beans from reaching the grinding mechanism.
- Less commonWorn or damaged burrs/bladesAfter years of regular use, grinding surfaces can dull or wear down significantly.
What to do
- Unplug the grinder and empty the hopper and grounds container completely.
- Check the grinding chamber for jammed beans or foreign debris and clear them out.
- Use a small brush to clean built-up coffee oil and fine particles from the burrs or blades.
- Reseat the hopper fully, making sure it locks or aligns correctly with the base.
- Try a slightly coarser grind setting to see if the issue is overload at very fine settings.
- If grinding remains inconsistent or absent after cleaning and clearing jams, the burrs or blades have likely worn out or the motor has failed, and replacement parts (for burr grinders) or a new unit may be needed.
Tools and parts
- Small brush
Replacement grinder burr set (model-specific)Search: “coffee grinder burr replacement”
When to call a pro
Burr replacement is possible on higher-end grinders and often worthwhile; for basic blade grinders, replacement of the whole unit is usually more practical.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.