Dyson PH04 Never going into standy/idle mode | Dyson Community

Dyson PH04 Never going into standy/idle mode

  • 23 November 2023
  • 2 replies


Firsty sorry for my bad english I am no native speaker.

I have set the air purifier up 3 days ago in the evening. I have set it on auto purify and auto humidify for more than 24 hours. It detects PM2.5, 10, VOC and so on very good and cleans it. But my main issue is the auto mode and the HCHO Formaldehyde Levels. The device never goes into standby. It always runs on at least fan speed 2 doing whatever. I think it tries to clean the formaldehyde but I am not sure. The HCHO levels stay at around 0.50-0,55 all the time. It never goes up or down. Even when the purifier is turned off the level barely changes. So I suspect the sensor somehow is not working. Once it reached 0,43 and 0,67. But I have never reached the auto setting where the device waits for the air to get bad and do something. 
Currently my PM2.5 level is 2 and so is the PM10. VOC and NO2 are on 0. HCHO is on 0,55 and the device runs consantly which is pretty annoying. I have it running for more than 72 hours now. Did a reset and turned it off just to monitor the air. If the device runs or not doesnt or barely makes a difference with the Formaldehyde levels. Is that something which is expected. I thought the pre set auto setting can always be achieved even when the device is cleaning these things. 

I dont seem to have a source of a lot of HCHO because with the device turned off the levels barely change. Also the Air Quality Report is not generating and it is not available since 3 days.

Can anyone help me? I am out of ideas. Thanks

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2 replies

@Nolon_Ksusk Thanks for the post. If it is detecting impurities in your air, it will keep purifying.
You can certainly try manual settings to turn off the fan. Or you may want to try in another area of your home to see if perhaps the room you are using it in has a perpetual presence of impurities in your air.

@Adam.Steinberg Thanks for writing.
It does not really matter where I place it in my home. It will show more or less the same HCHO levels. 

What I dont understand is that, on the Dyson Website it says that it “Even detects and destroys formaldehyde” which it clearly does not.

If I leave it running the Formaldehyde stays the same between 0.055 and 0.050. If I just turn it off and keep it monitoring the levels it shows the exact same result.

So I am wondering what is this purifier doing. Clearly not destroying formaldehyde. 

The other impurities work fine and are destroyed really well.

Also it would be nice If we could choose what the Auto Levels are. If I can tell the thing 0.055 is normal in my room and to shut off it would be great.

Any ideas?