From rim to flush system
What does rimless mean on a toilet bowl?
Rimless means the bowl has no enclosed, overhanging flush rim. Roca says that on its Rimless bowls the rimmed channel has been replaced, and that a distribution system spreads the water.
Geberit’s 2021 annual report says the iCon pan is designed without any rims or grooves or other hard-to-reach areas.
| Maker’s term | How the maker describes the bowl |
|---|---|
| Geberit Rimfree | No rim; a flush guide directs the water. |
| Duravit Rimless | An open flushing rim. |
| Villeroy & Boch DirectFlush | A rimless design. |
| TOTO Tornado Flush | A hole-free rim design. |
| Ideal Standard AquaBlade | No overhanging rim. |
| Roca Rimless | The rimmed channel is replaced. |
| Caroma CleanFlush | The rim of the bowl is removed. |
How does water rinse a bowl that has no rim?
Something other than a rim steers the flush water. Steps 1 to 3 follow Geberit’s 2021 annual report on the redesigned iCon toilets; steps 4 and 5 follow its Rimfree WCs page. They describe Geberit’s designs only.
- Flush water arrives at the inlet of the pan.
- A plastic flush guide takes it from the inlet.
- The guide directs it into the pan; Geberit says it does so without the water touching the ceramic appliance.
- The guide sends the stream along both sides.
- The stream reaches the area where Geberit says it is needed.
Other makers describe other paths. A photograph of an open bowl may not show which path a model uses.
Which water paths do makers describe?
The makers read for this guide describe a stream guided along both sides, a rotation started by nozzles or offset openings, and a vortex or spiral.
| Maker’s name | Water path the maker describes |
|---|---|
| Geberit Rimfree | A flush guide sends the stream along both sides. |
| Geberit TurboFlush | Water enters from the side in a spiral; the inner shape is asymmetrical. |
| Duravit HygieneFlush | Two offset openings set the flush stream in rotation. |
| TOTO Tornado Flush | Two nozzles create a centrifugal rinsing action. |
| Villeroy & Boch TwistFlush | A water vortex in a steep basin. |
| Roca Rimless Vortex | A 360-degree swirling flow; the inner surface is asymmetrical. |
Duravit Rimless and Villeroy & Boch DirectFlush are described more generally, as a flow that washes or rinses the entire inner surface. Duravit’s HygieneFlush page does not call the bowl rimless.
Is the rinse system the same across one maker’s range?
No, not at the makers read here. Villeroy & Boch and Roca each publish two named systems, Duravit names Rimless and HygieneFlush on separate pages, and Geberit describes two water paths for bowls it calls Rimfree: a flush guide along both sides, and TurboFlush. It lists its iCon series under both.
| Maker | Systems named | What the maker lists |
|---|---|---|
| Geberit | Rimfree flush guide; TurboFlush | Rimfree: Acanto, Smyle, iCon. TurboFlush: ONE, Acanto, iCon, Selnova and others. |
| Duravit | Rimless; HygieneFlush | HygieneFlush: White Tulip, ME by Starck, Bento Starck Box, Aurena. |
| Villeroy & Boch | DirectFlush; TwistFlush | DirectFlush: more than 20 models. TwistFlush: six collections. |
| Roca | Rimless; Rimless Vortex | Vortex: only In-Wash In-Tank smart toilets. |
Geberit’s 2021 report describes a newly developed flush guide for the rimless iCon toilets, and its 2025 report says iCon models now have TurboFlush. A display bowl and a current quotation may differ, so compare article numbers.
Which flush system does a rimless bowl need?
The word rimless names no cistern or valve; the model’s documents do. Keep the listed items on one schedule line.
Geberit TurboFlush
Geberit gives 2.6 litres for the small flush and 4 litres for the large, in combination with its Type 212 flush valve and the dual-flush actuator.
Villeroy & Boch TwistFlush
Villeroy & Boch gives a flush volume of 3 to 4.5 litres when the bowl is combined with a compatible, adjusted flush system, compared with 6 litres per flush.
WaterSense tank-type toilets
The labeling annex of the EPA’s specification says every combination of tank and bowl is to be tested and certified. Where tank and bowl are sold separately and are made by one maker, or by two makers that each hold a listing, the bowl packaging must name the counterpart tanks.
- Bowl model and article number
- Cistern or flush valve model
- Actuator or flush plate
- Flush volumes as set
Does a rimless bowl flush or clean better?
The label alone does not show that. Makers’ pages make four kinds of claim, each about a named system:
Cleaning access
Geberit says a Rimfree pan’s smooth inner surface is cleaned with one swipe, and that one can see at once whether all dirt has gone.
Rinse coverage
Ideal Standard says AquaBlade cleans 95% of the bowl every time; Villeroy & Boch says TwistFlush gives an almost 100% surface clean. Each figure is that maker’s own.
Splash
Villeroy & Boch calls the DirectFlush water flow splash-free. Roca describes a slight edge at the top of the bowl that keeps the water in. Caroma says controlled flow eliminates splash back.
Hygiene wording
Geberit says “germs have nowhere to hide” on its rimless toilets; Caroma uses similar words. This guide treats neither as a sterilisation result.
Do not rank rimless above rimmed on the label alone; ask for the test report for the offered combination.
Which standards and tests cover toilet bowl flushing?
Standards and label programmes address the toilet, rimless or not. Scope wording for the two standards is taken from standards bodies’ catalogue pages; the standards themselves were not read.
| Source | What its published text says |
|---|---|
| EN 997:2018 | Its published scope: requirements and test methods for close-coupled suites, one-piece and independent WC pans with integral trap; not flushing cisterns as separate appliances. |
| ASME A112.19.2-2024/CSA B45.1:24 | CSA Group says its performance requirements and test procedures apply to all types of water closets that discharge into gravity drainage systems. |
| WaterSense tank-type specification, version 2.0 (US) | The EPA limits the rated flush volume to 1.28 gallons per flush, for both modes of a dual-flush toilet; flush performance is tested by the ASME/CSA waste extraction test. |
| Makers citing EN 997 | Geberit says its tests show TurboFlush flush performance up to 10 times better than DIN EN 997:2018 requires. Villeroy & Boch says TwistFlush exceeds EN 997. |
How should a buyer specify a rimless toilet?
Specify the bowl and its flush equipment as one item. This is procurement guidance.
- Name the bowl. Maker, range, model and article number, not only “rimless”.
- Name the rinse system. Use the maker’s term and its description of the water path.
- Name the flush equipment. Cistern or valve model, actuator and the flush volumes as set.
- State the market. The installation type and the standard or label needed; confirm with the local authority.
- Ask for evidence. A test report or certificate for the offered combination.
- Keep one schedule line. A later substitution of the bowl or the flush equipment then shows up.
When a replacement bowl is proposed
Treat a bowl swap as a system change, even when both bowls are rimless. Recheck the model, the rinse system, the flush equipment and the connections, and record what changed.
What should you send and ask before a quotation?
Name the system, not only the look.
| Question | Why it matters |
|---|---|
| Which bowl model and generation is offered? | One range can carry more than one water path. |
| How does this bowl distribute the flush water? | Makers describe different water paths. |
| Which cistern or valve is it meant to use, at which flush volumes? | Makers state volumes with named or compatible flush equipment. |
| Which standard was the combination tested to? | Geberit and Villeroy & Boch cite EN 997 for their claims. |
| Is there a test report for coverage or splash claims? | A percentage on a page is the maker’s figure. |
Include with your request
- Project location and market
- Installation type and cistern arrangement
- Required standard, label or flush volume
- Quantity per room type
WNS Global confirms any offered toilet, flush equipment and commercial terms separately in writing. This guide does not state that WNS Global products are rimless, use any rinse system named above, or meet any flush volume, standard or label named above.
