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SickerDealer 12.8K Views
Sep 24, 2026 6:52 PM

Refurb: Dyson PH04 Humidify+Cool Formaldehyde Purifier

$300

$700

57% off
+ Free S&Hat Dyson
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Deal Details
Dyson has Dyson PH04 Humidify+Cool Formaldehyde Purifier (Refurbished, White/Gold) for $299.99. Shipping is free.

Alternatively, dysonofficial via eBay has Dyson PH04 Humidify+Cool Formaldehyde Purifier (Certified Refurbished, White/Gold) for $329.99. Shipping is free.

Note: Includes 2-year Allstate warranty when purchased via eBay. Final sale and may not be returned when purchased at Dyson.

Thanks to community member SickerDealer for finding this deal.

About this item:
  • The latest generation 3-in-1 Dyson Purifier Humidify+Cool Formaldehyde combines intelligent sensing with an advanced filtration and humidification system to purify, humidify, and cool you.
  • Three phases of purification sit within a fully sealed filtration and airflow system. So what goes inside, stays inside.
  • A solid-state formaldehyde sensor and a unique catalytic filter detect and continuously destroy formaldehyde, a HEPA filter captures 99.97% of particles 0.3 microns in size. Then powerful Air Multiplier technology projects purified, hygienically humidified air throughout the room. For a healthier, more comfortable environment.

Editor's Notes

Written by johnny_miller | Staff
  • Item condition:
    • Dyson
      • Dyson Renewed machines have been expertly serviced and hygienically cleaned. We test every machine to ensure it performs to our uncompromising standards. Any imperfections are purely cosmetic and can range from micro scratches and light scuffs to more visible marks, or discoloration to paint finishes and surfaces.
    • Dysonofficial via eBay
      • Our refurbished machines have been thoroughly tested to meet like-new performance standards. Units may have some cosmetic blemishes that include scratches and/or other surface imperfections, that do not affect functionality. Ships in non-retail box.
  • Please see the original post for additional details & give the forum comments a read for helpful discussion.

Original Post

Written by SickerDealer
Community Notes
About the Poster
Deal Details
Community Notes
About the Poster
Dyson has Dyson PH04 Humidify+Cool Formaldehyde Purifier (Refurbished, White/Gold) for $299.99. Shipping is free.

Alternatively, dysonofficial via eBay has Dyson PH04 Humidify+Cool Formaldehyde Purifier (Certified Refurbished, White/Gold) for $329.99. Shipping is free.

Note: Includes 2-year Allstate warranty when purchased via eBay. Final sale and may not be returned when purchased at Dyson.

Thanks to community member SickerDealer for finding this deal.

About this item:
  • The latest generation 3-in-1 Dyson Purifier Humidify+Cool Formaldehyde combines intelligent sensing with an advanced filtration and humidification system to purify, humidify, and cool you.
  • Three phases of purification sit within a fully sealed filtration and airflow system. So what goes inside, stays inside.
  • A solid-state formaldehyde sensor and a unique catalytic filter detect and continuously destroy formaldehyde, a HEPA filter captures 99.97% of particles 0.3 microns in size. Then powerful Air Multiplier technology projects purified, hygienically humidified air throughout the room. For a healthier, more comfortable environment.

Editor's Notes

Written by johnny_miller | Staff
  • Item condition:
    • Dyson
      • Dyson Renewed machines have been expertly serviced and hygienically cleaned. We test every machine to ensure it performs to our uncompromising standards. Any imperfections are purely cosmetic and can range from micro scratches and light scuffs to more visible marks, or discoloration to paint finishes and surfaces.
    • Dysonofficial via eBay
      • Our refurbished machines have been thoroughly tested to meet like-new performance standards. Units may have some cosmetic blemishes that include scratches and/or other surface imperfections, that do not affect functionality. Ships in non-retail box.
  • Please see the original post for additional details & give the forum comments a read for helpful discussion.

Original Post

Written by SickerDealer

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19 Comments

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Sep 27, 2026 5:46 AM
136 Comments
Joined Oct 2017
AsphericalDreamSep 27, 2026 5:46 AM
136 Comments

Our community has rated this post as helpful. If you agree, why not thank

Formaldehyde?
1
8
Sep 27, 2026 11:50 AM
14 Comments
Joined May 2022
EagerStove2128Sep 27, 2026 11:50 AM
14 Comments
Quote from AsphericalDream View quoted comment :
Formaldehyde?
Seriously wtf?
1
Sep 27, 2026 5:22 PM
2 Comments
Joined Oct 2023
RelaxedCorn792Sep 27, 2026 5:22 PM
2 Comments

Our community has rated this post as helpful. If you agree, why not thank

"A solid-state formaldehyde sensor and a unique catalytic filter detect and continuously destroy formaldehyde"
1
Sep 27, 2026 9:51 PM
1 Comments
Joined Jul 2025

This comment has been rated as unhelpful by Slickdeals users.

Sep 28, 2026 2:44 AM
872 Comments
Joined Jul 2022
VioletHealth8715Sep 28, 2026 2:44 AM
872 Comments
Darn if only the acid rain/napalm purifier was part of this deal. I've already got 2 formaldehyde purifiers.
10
Sep 28, 2026 5:24 AM
395 Comments
Joined Dec 2009
sfbrianclSep 28, 2026 5:24 AM
395 Comments
Hmm, could use the humidifier, but not sure how well that aspect works
Sep 28, 2026 9:02 PM
46 Comments
Joined Nov 2017
BroomcornSep 28, 2026 9:02 PM
46 Comments

Our community has rated this post as helpful. If you agree, why not thank

Just FYI these things break all the time because they put the motherboard of the humidifier in the stalk that goes into the water tank and then didn't waterproof it. Meaning, if moisture gets into it, the whole thing breaks down. Awful design
9
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Sep 28, 2026 10:45 PM
550 Comments
Joined Jul 2013
airj1012Sep 28, 2026 10:45 PM
550 Comments
Dyson under performs for air purifiers. Check out Fresh House reviews.
Sep 28, 2026 11:11 PM
724 Comments
Joined Dec 2017
DealArtistSep 28, 2026 11:11 PM
724 Comments
I always point people towards a corsi-rosenthol DIY air purifier using furnace filters. I've had the best results for wayy cheaper than other options, noticeable clean air. This one, I'll pass off to my coroner friend...
1
1
1
Yesterday 1:48 AM
15.9K Comments
Joined Feb 2007
sarcasmogratisYesterday 1:48 AM
15.9K Comments
$90 MSRP on replacement filters from dyson. Also looks OOS, unclear if still being made
There are knockoffs but who knows if they are decent quality.

https://www.dyson.com/support/jou.../974527-01
Yesterday 3:43 AM
15 Comments
Joined Sep 2017
bfisher2122Yesterday 3:43 AM
15 Comments
Quote from sfbriancl View quoted comment :
Hmm, could use the humidifier, but not sure how well that aspect works
Works great as a humidifier. Pro tip, put it in night mode otherwise the fan runs really loud if it's trying to keep up with a high humidity setting
1
Yesterday 7:15 AM
11 Comments
Joined Oct 2017
jjfnj4lawYesterday 7:15 AM
11 Comments
Quote from AsphericalDream View quoted comment :
Formaldehyde?
New Construction & Renovations BoomFormaldehyde is rampant in building materials — pressed wood, plywood, MDF, laminate flooring, and adhesives all off-gas it. Post-pandemic renovation waves and housing booms have put millions of people in freshly built or remodeled spaces with elevated formaldehyde levels.
Yesterday 10:53 AM
2.6K Comments
Joined Apr 2011
MIA2TLVYesterday 10:53 AM
2.6K Comments
Originally $1k?!
I know Dyson is pricey but damn!
Yesterday 11:26 AM
29 Comments
Joined Jun 2023
SiennaTable748Yesterday 11:26 AM
29 Comments
Quote from EagerStove2128 View quoted comment :
Seriously wtf?
Most new furnitures have and release formaldehyde over time, especially crappy ones made from engineered wood. Ppl in the US don't care as much as the rest of the world
1

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Yesterday 2:32 PM
68 Comments
Joined Sep 2011
tangogolfYesterday 2:32 PM
68 Comments
I got it as a humidifier, purifier is just an add-on. Too many variables to consider. Depends on the room size, heater settings in the winter, etc. Tbh, can't tell the difference as much as I wanted but the onboard sensor and another humidity sensor say that it does the job. It does go through a full tank of water fast and you need to continue refilling it.

I got mine through the Dyson site and the pump came broken out of the box. It was making extremely loud noise when it was using the water. I think it's a common issue and the reason why the stock of refurbished units always grows. Ended up shipping it back for repairs on day 1.
1

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