The PM2.5 sensor on my air purifier shows readings that drift over time
Home Nura guide — category: Air Purifiers
Diagnosis
This symptom isn't trivial, but in most cases you can still fix it without calling in a technician. Work through the steps below in order and stop as soon as the problem clears.
Recommended steps
1. Unplug the device and let it cool. 2. Look over the parts you can reach for visible damage. 3. Follow the manufacturer's procedure (manual or official website). 4. If the fix means taking the device apart, stop and contact customer support so you don't void the warranty.
Repair or replace?
If the problem persists after these checks and the appliance is no longer under warranty, compare the repair estimate with the cost of a new model.
If you decide to replace it
Air Purifiers: the shortlist from our buying guide
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Best overall
Levoit Core 400S
HEPA filter, a claimed 400 m³/h CADR, a laser PM2.5 sensor and sleep mode: versatile enough for a living room by day and a bedroom at night.
Photo: © Levoit
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Best value
Levoit Core 300S
Compact, with a HEPA filter, a claimed 240 m³/h CADR, auto mode and about 22 dB in sleep mode: the essentials for a bedroom.
Photo: © Levoit
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Quietest for sleeping
Blueair Blue Pure 411i Max
A claimed 18 to 46 dB noise range, washable pre-filter, PM2.5 sensor and app: ideal for noise-sensitive sleepers.
Photo: © Blueair
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Other common problems in this category
These issues affect the same type of appliance — each one comes with a diagnosis and the recommended steps.
Frequently asked questions
Usually, yes, if the failure shows up during the warranty period and isn't caused by misuse. A product in the Air Purifiers category bought new from an authorized retailer normally comes with a manufacturer's warranty: check its length in the manual or on the brand's website. Consumer protection rules also vary by province and territory, so keep your proof of purchase.
If you're still within the store's return window, a return or exchange is usually the fastest fix. After that, the manufacturer's warranty takes over: its customer support can arrange a repair or a replacement. Even outside the warranty, the manufacturer can often repair the device for a fee. Either way, keep your proof of purchase.
Our public methodology lowers the Nura Score /10 of any model in the Air Purifiers category whose recurring failures are documented in owner reviews. A model that breaks down too often never tops our rankings, whatever the brand.
Generally, yes. Routine maintenance, such as cleaning, replacing a gasket or recalibrating, is part of normal use and doesn't usually affect your warranty. Irreversible changes to the hardware are what can cause problems. For a product in the Air Purifiers category, stick to the steps described in the manufacturer's manual and read the warranty terms before going any further.
When a product fails in its first few months of normal use, the cause is usually a manufacturing defect. Contact the seller or the manufacturer with your proof of purchase and a description of the symptom: for a model in the Air Purifiers category that is still under warranty, this is the typical case for a free repair or replacement. Warranty terms vary by brand, so read yours.