How to clean an air purifier
In one line: unplug it, vacuum or wipe the outside and grilles, wash or vacuum the pre-filter, gently clear any sensor, and let everything dry fully before reassembling. Don't wash the main HEPA/MERV filter — that's replaced, not cleaned.
Step by step
- 1. Unplug it. Always switch off and unplug before opening.
- 2. Wipe the exterior & grilles. A dry or barely-damp microfibre cloth on the casing; vacuum the intake and outlet grilles where dust collects.
- 3. Clean the pre-filter. Most are washable/vacuumable — rinse under water or vacuum off the lint and hair, then dry completely. This is the biggest performance win (a clogged pre-filter throttles airflow).
- 4. Clean the sensor (if fitted). Air-quality sensors have a tiny vent that clogs with dust and then reads wrongly — gently clear it with a soft brush or a dry cotton bud per the manual.
- 5. Leave the main filter alone. The HEPA/MERV-13 filter is not washable — cleaning it damages the media. Vacuum its surface very gently at most, and replace it on schedule instead.
- 6. Dry fully & reassemble. Never put a damp pre-filter back — moisture can breed mould and clog the main filter.
Golden rule: pre-filters get cleaned; HEPA/MERV and carbon filters get replaced. See how often to change filters.
How often
Wipe/vacuum the exterior and pre-filter every 2–4 weeks (more with pets or heavy dust), check the sensor vent monthly, and replace the main and carbon filters on their schedule. Regular light cleaning keeps clean-air delivery up and the fan quiet.
Next step
Time to replace filters instead? See the filter change guide, and units that take standard, affordable filters at Best Air Purifier UK.
FAQ
Can you wash a HEPA filter? Almost always no — washing ruins the media. Only the pre-filter is washable; the HEPA/MERV filter is replaced.
Why is my purifier louder or weaker than before? Usually a clogged pre-filter or a spent main filter — clean the pre-filter and check whether the main filter is due for replacement.