Why does my fan blow air strongly on one setting but not the others?

If one speed works well but the others feel weak, the fan may be operating normally on its selected setting, or one of the controls may not be engaging each speed cleanly. Test each setting in turn so you can see whether the problem is with the control or with the airflow itself.

1. Switch the fan off and unplug it. Move the control to each setting in sequence and note whether the motor sound changes each time. A clear change usually means the fan is responding correctly.
2. Check whether any setting feels loose, slips between positions or needs a firmer click. If so, the external control may not be making proper contact.
3. Compare airflow on each setting with the fan facing you directly and with nothing blocking the grille. If the strongest setting still gives poor airflow, there may be a deeper fault.
4. Stop using the fan if one setting behaves erratically, if the motor sound changes suddenly or if the product becomes hot. Contact the retailer or store where it was purchased.

Expected result, the airflow should increase as you move through the settings. If the fan skips a setting, makes a crackling noise or responds unpredictably, stop using it straight away.