Winix air purifier red light: What it means and how to fix it

A red warning light isn’t the end of the world if you follow our step-by-step guide
Updated on April 15, 2024
Written by
Teddy Booth
Teddy joined HouseFresh in 2019 as a senior content producer, producing written content as well as product photography and YouTube videos. He supports Danny as a product tester and is our lead how-to writer.

A solid red light on your air quality indicator means that you have contaminated air and need to increase the unit’s fan speed.

A red warning light on the filter indicator means something is wrong with your filter.

Nine times out of ten it means your filter has run its course, and it’s time to replace it with a new one.

This red light can also indicate that your filter is dirty, installed incorrectly, or you haven’t reset the warning after replacing the filter.

Winix has a great range of air purifiers. We’ve bought a few ourselves and put them through their paces, like the 5300-2, 5500-2 and A231.

So we know as well as anybody that when a red light starts flashing on your Winix unit, it usually indicates that something’s wrong. This probably leads you to read through the manual (if you still have it) to determine what it means (if you can find it)… Cue the Indiana Jones theme song.

Well, you can put that hat and whip down because, in this guide, I’ll take you through what it means when a red light pops up on your Winix unit and how to fix it with little to no tools, no manuals and, best of all, no hassle.

What does the red light mean on my Winix air purifier? 

A Winix air purifier has a few possibilities of what a red light means. Modern Winix units usually come with an AQI (Air Quality Indicator) that displays the air quality in your room using a color bar.

If the color bar is red, it means your air quality is poor, and you’ll need to increase its fan speed so it works harder at cleaning airborne pollutants.

Another red light you are likely to find on a Winix air purifier is the indicator that warns you when the filter inside needs a little TLC.

Whether it’s replacing the filter completely or conducting a little maintenance, the red light will soon vanish like the harmful pollutants your Winix unit is removing from the air in your home.


If you have any other issues with your Winix air purifier, check out our full guide on 12 Common Winix Air Purifier Problems (and How to Fix Them)

Here are my top tips on fixing that pesky red light.

5 steps to fix the Winix air purifier red light warning

Before you try any of these steps, always remember to turn off your air purifier first and unplug it from the wall.

Step 1: Make sure the filter is installed correctly

Your Winix air purifier may think it needs a new filter, but sometimes, your filter might be installed incorrectly.


  1. Open up the filter compartment (this differs from unit to unit)
  2. Remove the filter
  3. Put the filter back in, making sure it’s installed correctly and fits snugly

Step 2: Check for blockages

You may be unaware of how much dust and dander your air purifier’s filter removes from your air, but it becomes clearly visible when you take a look at the filter itself. 

If the filter is blocked up with contaminants, it won’t work effectively and may cause your unit to think it needs a replacement.

While there, check to see that the fan is clear of blockages. This is the perfect time to give your air purifier a little clean so your air purifier can run smoothly.

Step 3: Clean your air purifier thoroughly

Sometimes, instead of replacing the filter when the red light comes on, you can get more life out of it with a little spring cleaning.

You must be gentle because if you damage the pleats in the filter, it will no longer work.


Check out our full guide on how to clean an air purifier to ensure you are thorough and avoid any damage.

Step 4: Replace your filter with a new one

If the previous steps don’t work, it’s time to bite the bullet and buy a replacement filter.

Unfortunately, HEPA filters don’t last forever, so when they are filled with particles, they become ineffective. The lifespan of a Winix filter is usually 12 months, but this can differ depending on how hard the filter is working.

Replacing a filter on your Winix air purifier is easy and painless:


Check out our YouTube channel, where we show you how to replace the filters on the units we’ve reviewed.

Step 5: Reset the filter indicator light

After each step, you must reset the filter indicator so the air purifier knows you have fixed/attempted to fix the issue. 

  1. Find the filter reset button (this is sometimes labeled, sometimes not, check the manual to find out)
  2. Press and hold the button for 5 seconds using a small object like a paperclip
  3. Release the button

If the red light comes back on, try another step on the list.

Common questions about the red light in Winix units

Some Winix models are different from others, but it is usually one of two methods to reset your air purifier.

  1. There will be a button labeled ‘RESET’. Press and hold this down for 5 seconds using a paperclip and release.
  2. In the absence of a reset button, there will be a tiny button next to the ‘check filter’ indicator.

It may be a fault with the air purifier itself (it is an electrical device, and sometimes they have faults). Contact the shop where you bought the unit, or you can contact Winix directly.


HEPA filters work by trapping pollutants from the air that flows through it. If your filter is clogged, then it will become ineffective and you’ll basically be running a big, pointless fan. 

This means your air purifier won’t output any clean air into your room.

The lifespan of any HEPA filter is conditional on how much pollution it is removing from your air. If you live in a highly polluted area (next to a highway, near a wildfire, extreme dust etc), you may need to change your filters more often than advised by the manufacturer.

With this in consideration, Winix advises that their filters have an expected lifespan of 12 months.

Technically, if the filter is full, you can, but don’t expect your unit to perform to its full capacity. As I mentioned above, when a filter is full of contaminants, it simply can’t trap anymore and stops being effective.

If it’s a fault with the warning light or one of the other issues highlighted above, simply reset the unit and use it normally.

Winix air purifiers that feature an AQI (Air Quality Indicator) use a smart sensor to monitor the quality of your air in real-time and display it on the unit’s control panel. This allows you to change the fan speed in accordance with the current amount of airborne pollutants in your room.

It shows this data using three colors:

Blue = Good air quality

Orange = Fair air quality

Red = Poor air quality

Final thoughts

A red light popping up on your Winix air purifier may seem scary but don’t worry, you don’t need to scramble through the trash looking for that manual (nobody keeps them anyway).

This is the most common fault on an air purifier and can be fixed with one of these five easy-to-follow steps.

90% of the time, the light indicates that the filter needs replacing, as all HEPA filters do periodically.

Remember, if none of these solutions work, contact Winix directly, as it may be a fault with the electrics in the air purifier.

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About the author

Teddy Booth

Teddy joined HouseFresh in 2019 as a senior content producer, producing written content as well as product photography and YouTube videos. He supports Danny as a product tester and is our lead how-to writer.

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