What’s Inside the Sonicare Airfloss?

My daughter can’t use floss because of her braces, so I got her a Sonicare AirFloss. It died after about a year, but she loved it so I got another. When it also died after a year, I got curious about what was going wrong.


I needed a band-saw to open an old Sonicare toothbrush, so I thought the AirFloss would be hard too. To my surprise, the bottom almost popped off with a little wiggling.  No potting or sonic welding here. Looks like that rubber O-ring is the only thing keeping the water out.


Now there’s your problem! Clearly the O-ring was not enough. Some water got down into the body and wrecked the PC board and battery inside.

On the next AirFloss, I’ll probably run a bead of epoxy around the body seam to keep this from happening again.

Since it is broken and I’ve got it open anyway, I wanted to see fancy compressor that generates the patented Microburst jet….


Hey! That’s just a spring loaded syringe plunger! It is actually a pretty neat little mechanism and the jet is surprisingly forceful. It could be useful in some project some day- maybe a tiny BB gun?

Here is what it looks like in action…


  1. David W

    In mine the tube came off inside and got tangled in the gears. Cleared the tubing out and it pumps again but I can’t figure out where the tube reconnects. I see two on your pictures but mine has less tubing than that. Looks like it should go from the reservoir to somewhere on a pump but I can’t see anything inside that white bit to put a tube on. Any more pictures?

  2. Phill R

    I found this fascinating. I have read an awful lot about the airfloss and it seems to get very mixed reviews. Some people love it and others hate it.

    I wonder if they release an update to make it more waterproof so people don’t have to put epoxy around it.

    I also think you are also onto something with the Sonicare mini BB gun :-)

  3. ejwu

    Do you still remember how to take this thing apart? I removed the bottom plastic cover and then got stuck. The whole electric/mechanical assemble won’t come out unless I cut the wires between the battery and the PCB. Or do I need to separate the pump (white plastic part) from the motor assembly (black plastic part) first?

  4. Clark Baker

    Thanks for this! My two week old one quit and was only making tiny vibrations.
    I pulled it apart (I put the bottom in a padded bike workstand clamp and helped with a sharp screwdriver as my was stuck pretty tight). I moved the gears around. Must have gotten stuck?? Maybe because it was so new and not worn in??

    I lubed the plunger with vasoline and the rest with synthetic grease (as those parts don’t(?) come in contact with the water.

    Thanks again. Saved me a new one.

    • bigjosh2

      Glad it worked, but next time when something fails under warranty… send it back! Phillps makes it a slight hassle because you have to call (no online path) during business hours- but it only takes a minute and you usually get the replacement within a week.

  5. LarryO

    Thanks for advice, Josh, on how to take apart. The O ring failed on my wife’s air floss, same as yours. We had to get another one. But I can now see that the corrosion was as bad as your daughter’s. Beyond repair. We love the air floss, it really does make a difference in the visits to the dental hygienist. Your advice will help be more careful with the ones we have left.

    • bigjosh2

      Maybe get some shrink wrap tubing at the hardware store that is big enough to fit around the flosser. They make this tubing with glue on the inside that melts to make a waterproof seal. Put that on and shrink it with a hair dryer. LMK how you make out!

  6. Charles R. Fricke

    What voltage is the battery? I am on my third one in three (3) year and Phillips claims no design flaws. HA. I would like to set mine up for an external power supply. I can cut the + and – battery conductors and connect directly. BTW mine has 4.04 vdc at the PCB.

  7. Red

    what about hanging the airfloss upside down in a stand. After you hang the floss in his hook you can put the charger foot on top. I love mine and already on number 4 and also stumbled on to this handy info. Will try the upside down charging option and be more careful wit cleaning under the running tap water. Mine always kills after 6 months. I also opened one from the first ones I was allowed to keep after it broke. It shows exactly the same corrosion at the same spot on the print.

    • Red

      my last one only kept 4 months working. I put a special glue around the handle to avoid water going inside the apparatus. Unfortunate it seems there is also water leaking inside the airfloss from a different spot. I have the feeling it’s the button at the top that gives the bursts. I will bring this one back to my dentist and when good I will get again a new one, muss be my 5 in 2 years and the old one back. I will open that one 2 and see what I find out about maybe another spot the water gets inside.

  8. Ahmed

    Wonder how to clean the insides, from the water tank to where the water flows out… water does leave residue that may make the machine unclean in short while!

    • Mical Wilmoth Carton

      I’ve had the same experience. My 1st Airfloss lasted 11 1/2 months. They sent a new handle. When the 2nd handle failed, after about another 15 months, I bought a second one. The second one failed after about 4 months, so I’m on my 4th handle in 3 1/2 years. Pretty ridiculous, but I also like using the Airfloss.

      • Charles Fricke

        I went through four (4) of them in three (3) years. Only had to buy one though due to the extended warranty. So I took the last one apart and found that the plunger had turned soft and sticky. This then over taxed the battery /motor and they die. They say you can use mouthwash, but it appears NOT. Customer service tells me there is no problem with them, yet look at the life cycle; less than a year. My wife had gone through two (2) of them and is on her third, BUT started using water and hydrogen peroxide (50/50) and this one seems to last.

        Customer Service knows about this, is quick to replace a failed unit under warranty, and could give a hoot after the warranty is up.

        I will NEVER buy another Philips product again.

        • Izzy G

          I also like using the product and have had several failures over 2-3 years. The current problem is that the battery won’t charge. Charger light glows a couple minutes then goes into hi frequency (dim) flash-perhaps 10/second, rather than slow on and off as it usually does when charging. How to replace battery?

  9. Letta Mego

    I bought one air floss. The cover for the water holder kept falling off and I finally lost it.
    Now I bought a new one and the very same thing happened…

    • Mical Wilmoth Carton

      I’m on my 4th AirFloss. I too really like using one. My first one lasted just under a year. My second lasted about 4 months. My third one last 4 days!!!! Thankfully Sonicare has replaced each of them without question. My current unit has been working fine for a few months, and I’m hoping it will continue to do so. Since each unit has failed before the warranty expired, I’ve only “purchased” one unit. Since they now have a two year warranty, I’m hoping they will either last longer than two years, or that I can continue to replace them under warranty.

  10. util

    My battery is on its way out, anybody know the dimensions ? Can’t see it in the photos. I’m assuming it’s just a 3.7v bat…

    • Heska

      At first I have to say thanks to this site, helped me to open my unit. :)

      Battery type is SL602444, dimensions are about 6 x 24 x 44 mm.

      Are You sure the problem is with the battery? Since seems like this is just a very bad desing, in my unit the tube got tangled in the gears and there was too much water inside, it was floating…

      Here is a cappy picture of the battery, but You should find it by simply googling with the battery type (SL602444) :

  11. JimBo9000

    In my case, the spring for the plunger mechanism was corroding. The corrision “washed down” the plunger causing excessive friction in the plunger mechanism. Apparently the plunger leaks.

    Typically I use mouthwash rather than water.


    I salute you with respect! I would be interested if anyone can tell me the mark on the transistor Q2 on the electronic board. The transistor on my board is destroyed and I could not identify what it was. Thanks in advance!

  13. Karel Auwerda

    I have the same problem, they last just a little over 1 year. I don’t think it is the O-ring, rather the tube where it connects to the reservoir. It is held there just by friction, and with the vibrations from the plunger system, it maybe only very little moisture leaking out, but enough to get something corroded.
    About Q2, it will be hard to replace, since it is surface-mounted. How do you know that that part is the (only) culprit?

  14. Mical Wilmoth Carton

    When I have purchased my AirFloss(es — two), I registered them immediately. Sonicare gives you additional warranty if you do this. Maybe 2 1/2 years? I’ve been able to use the warranty to good advantage. My first airfloss was replaced at least once in two – three years. My second is on its 2nd year, and it’s been replaced 3 times. When this one “expires,” I’ll replace it as well. I like using the Airfloss, and with the warranties, I feel like I’m getting my money’s worth.

  15. Gerard van Reekum

    I’m on my second. The first one was replaced by Philips with no cost. They must feel guilty. The second one wouldn’t hold the nozzle as the ‘click’ wore out. One and a half layer of conventional sellotape solved the problem. I checked the inside and it was dry. I may have damaged the O-ring by disassembling it, so let’s see if it stays dry :-) I admired the engineering of the power chords to the battery: they haven’t wasted a millimeter’s length, or one would be able to pull out the entire machine without desoldering the connections. These times we’re living in…

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