One Tank Clean product guide
Philips Sonicare Power Flosser & Toothbrush System 7000, HX3921/40 (White)
People who want the flosser and an electric toothbrush sharing one base
A countertop Power Flosser with four modes, ten intensity settings and a magnetic handle dock, combined with a Sonicare ExpertClean 7300 toothbrush that charges on the same base. Neither the listing nor the maker page states a tank size, and the brush has a separate manual.
Listing checked . Confirm the model, included parts and availability before ordering.
Published specifications
- Listing: model HX3921/40; 8.62 x 7.48 x 10.43 in; 3.27 lb
- Manual: four modes, Clean, Deep clean, Sensitive and Massage
- Manual: ten intensity settings on a base dial; start at lowest
- Manual: F1, F2 and F3 nozzles; only Philips flosser nozzles fit
- Manual: integrated Sonicare toothbrush charger on the same base
- Manual: two-year warranty; reservoir and nozzles excluded
Fit and limits
Strengths
- Flosser and toothbrush charge and live on one countertop base
- Four modes plus a ten-step dial, with a pacer you can switch off
- Nozzle storage case included in the manual's parts and cleaning lists
Caveats
- No reservoir capacity stated on the listing, maker page or manual
- Listing's detail table says a 9V battery is required; manual does not
- Warranty excludes the reservoir and nozzles, the parts that wear
One base that holds a water flosser and charges a toothbrush
This listing is the combined set: the countertop Power Flosser plus a Philips Sonicare ExpertClean 7300 power toothbrush, sold as model HX3921/40. Philips calls it the Power Flosser 7000 System, and the manual's title page names it the 7000 Power Flosser & Toothbrush system.
The manual's parts diagram lists a reservoir and lid, mode button and indicator, on/off button, intensity dial, hose and hose storage compartment, a Sonicare power toothbrush charger, the base, a magnetic handle dock, the flosser handle with pause switch and nozzle eject button, nozzles, a power adapter and a nozzle storage case.
The listing gives the product dimensions as 8.62 by 7.48 by 10.43 inches and the weight as 3.27 pounds, which is the footprint to measure against your counter. Philips describes the toothbrush charger as integrated into the same base.
Four modes and a ten-step intensity dial
The manual says this Power Flosser has four modes and names each one: Clean, described as standard water pressure with a pacer; Deep clean, using what Philips calls Pulse Wave technology; Sensitive, described as a gentle Pulse Wave mode; and Massage, which also runs the pacer.
There are ten intensity settings, changed with a dial on the base rather than on the handle. The manual asks you to start at the lowest setting for the first use and to raise the intensity over the course of a few weeks rather than immediately.
The pacer marks thirty second intervals by briefly pausing the flow, and the manual says it works on the Clean and Massage modes only. It can be switched on or off by holding the on/off and mode buttons together for five seconds, with the lights flashing once or twice to confirm.
Nozzles, the storage case, and what the box actually holds
The manual identifies three nozzle types by a code at the base of each nozzle: F1 Standard, F2 Comfort and F3 Quad Stream. Philips sells all three separately as HX3042/00, HX3052/00 and HX3062/00, each described on the maker page as two tips and compatible with Philips Sonicare Power Flossers only.
The manual is explicit that the contents of the box may not include every item shown, because that depends on the configuration purchased. Neither the listing nor the Philips product page prints a nozzle count for HX3921/40, so check the box contents on the listing page before assuming which nozzles arrive.
A nozzle storage case appears in the manual's parts list and again in its cleaning section, where the case is described as hand washable in warm soapy water or dishwasher safe. The manual also says only Philips Sonicare Power Flosser nozzles fit, and that AirFloss nozzles do not.
Two things the documents do not settle
Neither the listing, the Philips product page text nor the English pages of the manual states a reservoir capacity in millilitres for HX3921/40. The Technical Specifications panel on the Philips page did not load, so if tank size matters to you, ask Philips rather than assuming it matches another model in the range.
The listing's own detail table carries a line saying one 9V battery is required. The manual describes the unit as mains powered through a supplied adapter into a 100 to 240 volt outlet and does not mention a 9V battery anywhere in the English pages that were read.
Neither document explains that difference, so treat the battery line as unconfirmed and check with the seller or Philips before buying anything on the strength of it. The magnetic dock is described in the manual as resetting the handle's pause switch to off when you dock it.
Weekly cleaning, six-month nozzles, and tank contents
The manual says the product needs cleaning once a week. The reservoir and lid can be hand washed with warm water and mild soap or put in the dishwasher, and the outside of the base and handle are wiped with a soft cloth and mild soap when needed.
For clogged nozzles the manual gives a white vinegar soak every few months, and a separate vinegar flush for the internal components, hose and handle. The mixing ratios and soak times belong to the manual and are not reproduced here, so read that section before you mix anything.
Nozzles are to be replaced every six months or immediately if damaged. On what may go in the tank, the manual's question list says essential oils are not recommended, that mouthwash can be mixed with water, and that the unit should be rinsed through with water afterwards.
Two-year warranty, and a toothbrush with its own manual
The manual states a two-year warranty from the date of purchase against defects in materials and workmanship, on convincing proof of purchase. Philips' product and support pages both carry a matching two year warranty badge, and the support page offers an extended warranty if you register within ninety days.
The written exclusions are the reservoir, the nozzles, damage caused by unauthorised replacement parts or nozzles, damage from misuse, abuse, neglect, alterations or unauthorised repair, and normal wear such as chips, scratches, abrasions, discoloration and fading. Philips also warns that other nozzles may limit warranty protection.
For the toothbrush half of the set, the flosser manual points you to a separate toothbrush manual for charging instructions and charging times. That document was not read for this page, so confirm the brush's own details, including its brush heads and app, with Philips.
Check the current listing
Confirm the model, included parts and availability before ordering.
Primary sources
- Philips product page for the Sonicare Power Flosser 7000 System HX3921/40
- Philips support page for HX3921/40, listing the User Manual
- Philips Sonicare Power Flosser 7000 User Manual (PDF)
Primary sources checked .
Compare with
- Waterpik Aquarius Countertop Water Flosser WP-660 (White)
A bathroom counter near a North American outlet, shared by several people
- Waterpik Cordless Advanced Water Flosser WP-580 (White)
Travel, small bathrooms or flossing in the shower
- COSLUS C20 Cordless Water Flosser, F5020E (Black, Professional Set)
People who want a cordless flosser with a 300 ml tank and a published PSI range
- Philips Sonicare Cordless Power Flosser 3000, HX3826/21 (White, 2 Nozzles)
People who want a cordless flosser for one short session a day
- Waterpik Cordless Pulse 3100 Water Flosser, WF-20CD010 (White)
Light daily use and travel where a small tank is acceptable
- Waterpik Aquarius Countertop Water Flosser WP-667 (Modern Gray)
A shared bathroom where several people want their own tip and pressure setting
Side-by-side pages, this model next to: Philips Sonicare Countertop Power Flosser 5000, HX3811/20 (White, 2 Nozzles), Philips Sonicare Cordless Power Flosser 3000, HX3827/21 (White, 4 Nozzles).