How to Remove “F” Code on Your Dyson Air Purifier (Easy Fix)

When your Dyson air purifier displays an “F” code with three flashing bars, it indicates that the filter needs to be replaced. Dyson filters generally last around 12 months of regular use (approximately 12 hours per day). So you can expect to see this filter reminder code about once a year under normal conditions.

However, the main challenge with this code lies in the filter replacement process, because many people aren’t familiar with how to reset the indicator after installing a new filter.

Below, I’ll break down exactly what to do when you see the “F” code, and discuss how this code (and other Dyson “F” error codes) may vary across different Dyson models.

Quick Fix: Replacing the Filter and Resetting the Indicator

To clear the blinking “F” code, you must replace the old filter with a new one and then reset the filter life indicator. Here are the steps to do this:

1. Turn off and unplug the air purifier. For safety, switch off your Dyson and disconnect it from power before replacing the filter.
2. Remove the old filter and install a new genuine Dyson filter. Dyson filters are not washable or reusable – they are non-washable filters that must be replaced when spent. Follow your model’s manual for filter replacement. Typically, you press the release buttons to open the filter housing, then take out the used HEPA/carbon filter and fit the new filter in place, ensuring it’s seated correctly.
3. Plug the machine back in and reset the filter indicator. Dyson air purifiers won’t automatically clear the “F” alert after you change the filter – you need to manually reset it. The easiest way is by using the Dyson remote control: point it at the air purifier and hold down the Standby ON/OFF button for about 6 seconds until you see the display countdown or flash, indicating the filter life has been reset. On models with the Dyson Link app, you can also reset the filter through the app’s settings (look for a “Reset filter life” option in the app and follow the on-screen instructions).

After these steps, the “F” code should stop blinking. Your air purifier’s filter counter will be reset to 100%, and you’re all set until the next filter change is due.

Is the “F” Code the Same on Every Dyson Air Purifier?

Not exactly. While “F” generally relates to filter maintenance on Dyson air purifiers, the way it’s displayed and the reset procedure can differ by model:

• Older Dyson Purifiers (e.g. Pure Cool Link series like TP01/TP02): These models have basic displays and typically show a blinking “F” (sometimes with bars) when the filter needs replacing. The reset is done via the remote as described above. There is no fancy LCD readout – just the letter “F” on the unit’s small display.
• Newer Dyson Purifiers with LCDs (e.g. Dyson Pure Cool TP04, Pure Hot+Cool HP04, etc.): These have more detailed displays. Instead of a simple “F” character, the machine might show a graphic icon (often a red filter icon or a triangle warning symbol with an “!”) to indicate the filter is dirty. For example, some Dyson models display a red outline of a filter with an exclamation mark when it’s time to change the filter, rather than the letter “F”. The core meaning is the same – the filter needs attention – but it’s presented in a more visual way. After replacing the filter, you still need to reset the indicator via the remote or Dyson app (the machine’s screen may show a short countdown to confirm reset).
• Dyson Models with Dual Filters (separate HEPA and Carbon filters): A few Dyson air purifiers (mostly newer models like the TP04/HP04 series and onwards) use two filter types that may need individual resets. In these cases, the “F” code or filter warning might specify which filter needs to be replaced. To reset dual-filter models: you typically hold the Night Mode (moon) button for 5 seconds to reset the HEPA filter life, and hold the Oscillation (↔ arrows) button for 5 seconds to reset the carbon filter. The device’s display will count down from 5 and confirm each reset. Make sure to do both if your purifier uses both filters, otherwise, it may continue showing a filter alert for the second filter.
• Smart Dyson Purifiers (Dyson Link App-enabled): Any Wi-Fi-connected Dyson purifier allows you to monitor filter life in the app. You can also reset the filter indicator through the app after installing a new filter. This is often the most straightforward method – the app typically will prompt you when a new filter is installed or if it detects the filter’s life is at 0%. Just follow the in-app instructions to confirm you’ve replaced the filter, and it will reset the counter.

In summary, most Dyson air purifiers will show some form of an “F” alert for filter replacement, but the exact code or icon and the reset method can vary.

Always check your model’s user manual for the precise procedure. If you hold down the wrong button (for example, pressing a button on the machine itself instead of using the remote), you might inadvertently reset something else – holding the physical power button on some Dyson units will reset the WiFi connection, not the filter indicator, which can be confusing. So stick to the instructions for your specific model or use the app.

What Are Other “F” Codes on Dyson Air Purifiers?

Besides the routine filter replacement reminder, Dyson air purifiers (and humidifier or fan combo units) can display several other “F” codes accompanied by numbers. These typically indicate various faults or conditions. Here are the common ones and what they mean:

Dyson F1 Code

Meaning: This code often appears on Dyson humidifier models (or air purifier-humidifier combos) and indicates a problem with the piezoelectric element. The piezo is the ultrasonic component that atomizes water in Dyson humidifiers. In plainer terms, an F1 error means the machine’s water vaporizer (piezo) isn’t working correctly (it could be due to mineral buildup, a faulty sensor, or a failing piezo unit).

How to Fix: Turn off and unplug the machine, wait 60 seconds, then plug it back in and power on. This acts as a basic reset. If the F1 code persists, Dyson’s guidelines for humidifiers suggest that the piezo unit may need replacement. Try cleaning the humidifier’s base and piezo element (if you haven’t recently done a deep clean/descale, buildup could be an issue). If that doesn’t help, you may need to contact Dyson support or a technician to replace the piezo assembly.

Dyson F2 Code

Meaning: The F2 code applies only to Dyson devices equipped with UV-C lights (again, mainly the humidifying models, such as the Dyson AM10 Humidifier or Pure Humidify+Cool series). It indicates an issue with the UV-C emitter lamp that sterilizes the water. In other words, the UV light that kills bacteria in the water tank might not be functioning properly.

How to Fix: The initial fix is the same reset procedure – turn off and unplug for 60 seconds, then plug in and restart the machine. Repeat a couple of times if needed. If the F2 error still comes back, it likely means the UV-C lamp has failed or isn’t detected. The lamp might need to be replaced. Dyson’s support site provides guides for replacing the UV-C bulb on applicable models. If you’re not comfortable doing that, contact Dyson support for service.

Dyson F3 Code

Meaning: An F3 error usually means your device is too cold. Dyson humidifiers and some air purifiers will display F3 and shut down if the ambient temperature falls below about 5°C (41°F). This is a protective measure, particularly for humidifiers, to prevent operation in freezing conditions (water could freeze or the machine may not function optimally when it’s very cold). Interestingly, users have also reported F3 codes on some pure-cool fan models in cool rooms, suggesting it’s a general low-temperature cutoff or sensor issue.

How to Fix: Move the Dyson to a warmer environment and allow the room to warm above 5°C. To reset the code, turn the device off, unplug it for 60 seconds, then plug it back in. It may take a few power cycles once the room is warmer. Also, ensure you’re not using the air purifier in an unheated space in winter – they aren’t designed to run below 5°C. Once the ambient temperature is above the threshold, the F3 warning should clear and the unit will operate again. (No actual filter replacement is needed for an F3 code – it’s purely temperature-related).

Dyson F4 Code

Meaning: Dyson hasn’t officially published detailed explanations for F4 in their user manuals (they generally just advise resetting and contacting support if it persists). However, anecdotal evidence and some experts suggest F4 is often related to the fan motor or a general fault, and in the context of air purifiers, it can also be triggered by an incorrect filter installation. For example, if you just changed the filter and see F4, it might mean the new filters are not seated or locked in properly, or the filter cover isn’t closed all the way, causing the machine to detect something is off.

How to Fix: First, try the standard reset: turn off, unplug 60 seconds, then plug in and restart. If F4 appears immediately after a filter change, double-check your filters – turn off and unplug the unit, then remove and re-install the filters correctly. Ensure any filter housing clips or covers are secured fully. Then plug in and turn on the machine again. You can attempt the 60-second power cycle a couple of times. If the F4 code continues to flash even after reseating filters and resets, there might be a deeper issue (some owners have reported F4 when the internal fan was jammed or the PCB had a fault). In that case, it’s best to contact Dyson support or have the unit serviced.

Dyson F5 Code

Meaning: F5 is typically a sensor error or system fault. Dyson support documentation for some models groups F5 with F4 and F6 as faults that can be reset. According to one appliance repair source, an “F5” may indicate a malfunction in one of the air purifier’s sensors (for example, the particulate sensor, gas sensor, or another internal monitoring sensor). Essentially, the machine thinks a sensor isn’t responding properly.

How to Fix: As with F4, start with the simple fix: turn off and unplug the air purifier for a minute, then restart. Do this up to 3 times. If the F5 error persists, you likely cannot solve it through DIY means beyond checking for obvious issues (like making sure the machine is clean and filters aren’t causing blockage). An F5 often requires contacting Dyson customer support for further guidance. They might walk you through additional troubleshooting (like cleaning the particle sensor inlet with a soft brush or ensuring no dust is clogging any vents) or advise a repair if a sensor or circuit has failed.

Dyson F6 Code

Meaning: The F6 code is less commonly reported, but some sources suggest it can appear on Dyson air purifiers as an air quality alert rather than a fault. In those cases, F6 would mean the air purifier has detected very poor air quality or high pollutant levels in the room. Think of it as the machine saying “Air quality is bad right now.” (Note: On many Dyson models, poor air quality is usually indicated by a color change on the display ring or a high number on the PM2.5/PM10 readouts, rather than an F6 code. So F6 might be a more obscure or model-specific code.)

How to Fix: If F6 truly corresponds to an air quality warning, it’s not an error with the machine, but rather information for you. In this scenario, you don’t “fix” the code; instead, you let the air purifier continue running to clean the air. You might consider increasing the fan speed or turning on Auto mode so the Dyson works harder to reduce pollutants. Once the air quality improves, the notification should clear. However, ensure that it’s actually an F6 code and not a misread of another code. If the machine isn’t running at all or the code is blinking, it could be something else. When in doubt, refer to the manual or contact Dyson to interpret an unfamiliar code.

Dyson F7 Code

Meaning: An F7 error points to an overheating condition in the air purifier. This code may appear if the device’s internal components get too hot. Dyson machines have built-in safety cut-outs for overheating (for instance, the heater in a Hot+Cool model will shut off if it overheats, and apparently it may throw an F7 in such cases). Overheating could result from blocked air flow, very high room temperature, or an internal component fault.

How to Fix: Turn off and unplug the air purifier immediately if you see an F7 code. Allow it to cool down for at least 30 minutes. Check for any obstructions: make sure the air inlet holes and outlets are not blocked by dust or placed too close to walls or furniture. After it has cooled completely, plug it back in and turn it on again. Ensure the machine is in a well-ventilated space. If it runs without the code, it may have been a one-time overheat (for example, on a hot day). But if F7 recurs, do not continue using the machine – there could be an internal failure like a bad fan motor or thermostat. In that case, reach out to Dyson support for repair, as an persistent F7 error may require service.

F8, F9, etc.

Dyson doesn’t commonly use F8, F9 codes in their air purifier lineup (those haven’t been documented in consumer experiences widely). In general, any “F” code means the unit has detected something that needs your attention – if it’s not one of the above known codes, it could be specific to a particular model or a newer code. Always refer to your user manual’s troubleshooting section for a list of fault codes. If the manual doesn’t clarify it, contact Dyson support with the exact code and your air purifier model.

Note: Some Dyson products (like pure heater fans or older models) also have C codes or H codes for other issues (for example, “H2” for a thermostat issue in heating mode, etc.). These are outside the scope of the “F” filter codes, but keep in mind that not every letter code on the display will be an “F”. The strategy for any of them is similar – check the manual, reset the machine, and contact support if it won’t clear.

FAQ on Dyson Code “F”

Final Thoughts

Seeing an “F” code with three bars on your Dyson air purifier is not a cause for alarm – it’s a routine reminder that your filter is used up and needs replacing to keep cleaning your air effectively.

B installing a fresh filter and resetting the filter life indicator, you’ll resolve the blinking “F” code.

Keep in mind the slight differences between models: always follow the specific reset procedure for your unit (when in doubt, check the user manual or Dyson’s online help for your model). If you encounter any other F-coded messages (like F1, F2, etc.), use the troubleshooting tips above to address them. Most can be solved by simple steps like power cycling or part replacements. And for any persistent or unclear error code, Dyson support is there to help – don’t hesitate to contact them if needed, especially while your air purifier (or humidifier) is under warranty.

If you have any questions about your Dyson air purifier, feel free to leave a comment in the comment box below. I will make an effort to respond to every comment as quickly as possible.