Rimless design and washdown flushing are two separate engineering decisions, not one feature. A rimless wall-hung toilet has no internal rim ledge, so there is no concealed channel where residue and mineral deposits collect. A washdown flush discharges water around an open bowl perimeter and clears the pan using water volume, velocity and bowl geometry rather than a siphon jet. When both are combined in a wall-hung pan, the fixture is specified by four things: bowl geometry, flush system, ceramic body, and certification scope for the destination market.

This technical guide works through those four specifications using the FI-20 wall hang pan as the reference model. The FI-20 wall hang pan is a wall hung toilet with a rimless bowl and a washdown flushing system, measuring 495 x 365 x 365 mm and made from high-temperature fired ceramic, a type of ceramic sanitary ware. It is produced by Tangshan Houfengyuan Import and Export Co., Ltd, a ceramic sanitary ware manufacturer and exporter based in Tangshan City, Hebei Province, China, which supplies ceramic toilets and ceramic wash basins to buyers in the USA, Canada, Australia, the Middle East, Southeast Asia and Europe, with roughly 90% of output exported.

Why Rimless Washdown Wall-Hung Toilets Are Mis-Specified

Most specification errors on rimless washdown wall-hung toilets fall into five categories: dimensions, flush system, cleaning assumptions, ceramic body, and certification scope. Each one can be resolved before an order is placed, using information that is already available in the product specification.

• Pan dimensions are not installed dimensions. The FI-20 wall hang pan measures 495 x 365 x 365 mm. Those figures describe the ceramic pan itself. The finished footprint also depends on the in-wall carrier system, the finished wall build-up, and the seat and cover fitted afterwards. Teams that plan layout and tiling from the pan dimensions alone usually have to revise drawings later.
• Washdown and siphonic are not interchangeable terms. A washdown toilet clears the bowl through water discharge and bowl geometry. A siphonic toilet uses a siphon jet and trapway to pull the contents away. In the same Ceramic Sanitary Ware range, the FTO-8848 one-piece toilet and the FTZ-0420D two-piece toilet are siphonic models, while the FI-20 wall hang pan, the FI-20 back to wall pan, the FI-05 wall hang pan and the FI-05 back to wall pan are washdown rimless models. Both systems work; they suit different plumbing conditions and different maintenance regimes.
• Rimless is a cleaning decision, not a water-volume decision. Removing the rim ledge removes the hidden surface where residue accumulates. Flush volume is set separately from bowl geometry, and the FI-20 family can be ordered in different flush volumes (see the customization section below).
• The ceramic body determines how the pan behaves over years, not weeks. High-temperature fired ceramic is the material used across the range; the glaze finish is what carries the day-to-day cleaning promise.
• Certification scope is market-specific. WaterMark applies to the Australian and New Zealand markets; cUPC applies to the USA and Canada. A product listed for one market is not automatically accepted in another, and commercial projects frequently require the listing to name the exact model.

Industry Background: What Is Driving Rimless Washdown Demand

The demand for rimless washdown wall-hung pans is being pulled by commercial construction rather than by residential replacement alone. According to Grand View Research, the global ceramic sanitary ware market was estimated at USD 44.3 billion in 2023 and is projected to reach USD 80.99 billion by 2030, a CAGR of 9.4%. Precedence Research reports that Asia Pacific dominated the market in 2024 with a 54% revenue share, with China and India as the primary growth engines.

Supply is concentrated in the same region. MECS / Ceramic World Review data indicates that China's exports of sanitary ceramics reached 2.17 million tonnes in 2024, equal to 58.4% of global total export volume. A-Diffusion, citing China Customs data, puts China's total sanitary ware export value for 2024 at USD 15.637 billion, a 4.69% year-on-year decrease, which points to an increasing-quantity, decreasing-price pattern across the category. For buyers, that combination means supplier selection and specification accuracy matter more than headline pricing.

On the demand side, Mordor Intelligence notes that commercial applications, including hotel projects, are expected to exhibit the highest CAGR as tourism sectors recover — the segment where rimless bowls and easy-clean glazes are most often specified. Compliance pressure reinforces the trend: cUPC is described by IAPMO as a mandatory compliance requirement for many commercial and government plumbing projects in North America, while WaterMark is the primary requirement for plumbing and drainage products in Australia and New Zealand. Published market-size estimates vary with product scope — Market Research Future and Research Nester publish materially different figures for the same category — so buyers should treat any single market number as an indicator of direction rather than a precise specification input.

FI-20 Wall Hang Pan: Technical Specifications and Engineering Details

The FI-20 wall hang pan is a Ceramic Sanitary Ware wall-hung toilet with a rimless bowl and a washdown flushing system. Its verified specification is compact enough to summarise in a single list.

Rimless bowl geometry: what actually changes for cleaning

A conventional toilet has a rim that forms an internal channel around the bowl. Water is distributed through that channel, and the channel itself becomes an inaccessible surface. A rimless bowl removes the ledge, so the water path and the visible bowl surface are the same surface. In practice, this changes three things: housekeeping staff spend less time on concealed surfaces, descaling is easier because the entire bowl wall is reachable, and the bowl geometry can be evaluated visually rather than inferred. Rimless design is therefore a maintenance decision first and an aesthetic decision second — which is why it is frequently specified for hotel projects and apartment decoration programmes with high fixture turnover.

Washdown flushing: how the mechanism works and where it fits

A washdown toilet relies on the force of water entering the bowl combined with the contour of the bowl and trapway. There is no siphon jet to be blocked, and no narrow jet orifice to scale up in hard-water conditions. That is the engineering reason washdown pans are often selected where water quality is variable or maintenance intervals are long. The trade-off is that washdown performance depends more heavily on flush volume and bowl contour than a siphon system does, so the bowl must be specified as a system rather than as a shape. Buyers comparing a rimless washdown pan with a high flush anti-clog siphonic model should compare the two on plumbing conditions and service access, not on the word "rimless" alone.

High-temperature fired ceramic and the glaze surface

Every model referenced in this guide — the FI-20 wall hang pan, the FI-20 back to wall pan, the FI-20 two-piece toilet, the FI-05 wall hang pan and the FI-05 back to wall pan — uses high-temperature fired ceramic as its primary material. Firing is carried out in tunnel kilns: one 126-metre-long, 3.2-metre-wide kiln and two 82-metre-long, 2.8-metre-wide kilns. According to the manufacturer, these kilns are characterised by low unit energy consumption, evenly controlled cross-section temperature at each stage, and an adjustable firing curve, which allows firing to be tuned to product requirements. For a buyer, the practical implication is repeatability: an adjustable firing curve is what allows a rimless bowl to hold its form across production batches.

The cleaning performance a rimless bowl delivers depends on the glaze that covers it. The manufacturer describes its products as having durable quality, glossy and easy-to-clean glazed surfaces, and water-saving and energy-saving features. Easy-clean glaze and a rimless bowl are complementary: the rimless geometry removes the hard-to-reach surface, and the glaze determines how easily the remaining surface releases residue.

Wall-hung installation and dimensional planning

Wall-hung installation moves the fixture off the floor, which frees floor area and simplifies cleaning underneath the pan. The planning consequence is that the wall must carry the load, and the ceramic pan is only one part of the dimensional chain. When planning a wall-hung specification, three dimensions should be confirmed on the same drawing: the pan size, the in-wall carrier position, and the finished wall face. For reference, the manufacturer's wall-hung and back-to-wall options include the FI-20 wall hang pan at 495 x 365 x 365 mm, the FI-20 back to wall pan at 520 x 365 x 420 mm, the FI-05 wall hang pan at 517 x 360 x 365 mm, and the FI-05 back to wall pan at 520 x 360 x 420 mm. Where a floor-mounted configuration is preferred instead, the FI-20 two-piece toilet measures 660 x 365 x 420 mm and the FI-05 two-piece toilet measures 660 x 360 x 420 mm.

Certification coverage by market

Certification is where a rimless washdown specification is either accepted or rejected on site. Tangshan Houfengyuan holds a WaterMark Certificate of Conformity, certificate number WMK26227, issued by SAI Global for the Australian market, covering water closet pans, flushing devices and cistern inlet and outlet valves under AS 1172.1-2014 (Amdt 1 2018) and AS 1172.2-2014 (Amdt 1 2018). The certificate was issued on 12 February 2022 and is valid until 10 July 2027. Its listed products include the FI-20, the FI-20 back to wall pan, the FI-20 wall hang pan, the FI-05, the FI-05 back to wall pan and the FI-05 wall hang pan.

For North America, the company holds IAPMO R&T cUPC product listings: File No. 6560 for ceramic plumbing fixtures — water closets, lavatories, urinals, bidets, service sinks and drinking fountains — under ASME A112.19.2-2024/CSA B45.1-24; File No. 6559 for water closets with a dual flush feature under ASME A112.19.2-2018/CSA B45.1-18 and ASME A112.19.14-2013; and an EPA WaterSense listing, File No. 6561, for high-efficiency toilets for the USA market. Production is also covered by an ISO 9001:2015 quality management system certificate issued by the China Quality Certification Centre (CQC) for the production of sanitarywares.

Step-by-Step: How to Specify a Rimless Washdown Wall-Hung Toilet

The specification sequence below follows the order in which the decisions actually constrain each other. Skipping forward — for example, choosing a glaze before confirming the market certification — is what creates rework at the procurement stage.

1. Fix the installation type. Decide between wall-hung, back-to-wall and two-piece before comparing sizes. The FI-20 family covers all three configurations, so the choice is driven by the project, not by availability.
2. Confirm the wall structure and carrier position. For wall-hung installation, the carrier and finished wall face must be coordinated with the pan dimensions on the same drawing. The pan figure of 495 x 365 x 365 mm is a starting point, not an installed dimension.
3. Set the bowl design and flush system. Rimless plus washdown is the configuration described in this guide. If a siphonic system is preferred, it should be specified as a different product — for example a siphonic model from the same range — rather than assumed.
4. Select the flush volume. Flush volume is a customization parameter and can be specified as 1.28/1.6 gpf or 3/6 L. This is where water-saving ceramic sanitary ware requirements are resolved, and where local water-efficiency expectations should be checked.
5. Check the cleaning regime. Confirm the glaze expectation against housekeeping practice. Easy-clean glaze and a rimless bowl should be specified together; one without the other reduces the benefit.
6. Verify certification for the destination market. WaterMark for Australia; cUPC for the USA and Canada. Confirm that the certificate product list names the exact model being ordered, not only the family.
7. Define OEM and ODM requirements. Customization covers logo, colour, flush volume, bowl shape (round or elongated), tank design, seat height (standard or ADA comfort height), packaging and private labelling.
8. Agree the acceptance criteria. The manufacturing control standard is 100% inspection, with water testing performed on every piece.
9. Plan lead time and commercial terms. Quoted lead time is 35–45 days, with a monthly capacity of 290,000 units, a minimum order quantity of 50 units, FOB delivery terms, 30/70 payment terms, and a 3-year warranty.

Where Rimless Washdown Wall-Hung Toilets Fit

The configuration is most useful where cleaning time, water consumption and long-term maintenance all matter at once. Four project types recur in the manufacturer's stated application scope of construction & engineering projects and wholesale distribution.

Hotel project ceramic sanitary ware

Hotel bathrooms are cleaned daily by staff who are not the end users. A rimless bowl removes the concealed surface that consumes the most housekeeping time, and a wall-hung pan removes the floor joint where grout discolours fastest. This is the segment Mordor Intelligence identifies as the fastest-growing commercial application.

Apartment decoration ceramic sanitary ware

Multi-unit residential projects specify in volume, so a single verified model with a repeatable finish matters more than a wide catalogue. The FI-20 wall hang pan's fixed 495 x 365 x 365 mm footprint and its listing under WaterMark WMK26227 make it straightforward to repeat across identical bathrooms.

Water-saving and high flush anti-clog requirements

Where water efficiency is the driver, flush volume is specified through the customization programme at 1.28/1.6 gpf or 3/6 L. Where clogging risk is the driver, the washdown mechanism is relevant because it has no siphon jet orifice to block — although the flush volume and bowl contour still need to be confirmed as a set.

Wholesale distribution and construction & engineering projects

Distributors need a model that can be reordered with consistent dimensions and documentation. A listed model with a named certificate, a fixed specification and a stated 35–45 day lead time is easier to commit to stock than an unlisted one, particularly when the destination market is Australia or North America.

Verified Comparison Table: Rimless Washdown Models and Wall-Hung Options

The first table compares the rimless washdown pans covered by WaterMark Certificate of Conformity WMK26227. Every value below is taken from the model specification; no estimated or interpolated figures are used.

The second table lists other wall-hung models in the range that use a washdown system, so that buyers comparing wall-hung options can see the dimensional spread. Rimless bowl design is specified on the FI-20 and FI-05 families.

Frequently Asked Questions

Which certifications cover the rimless washdown wall-hung models in Australia and North America?

For Australia, the WaterMark Certificate of Conformity WMK26227 issued by SAI Global covers water closet pans, flushing devices and cistern inlet and outlet valves under AS 1172.1-2014 (Amdt 1 2018) and AS 1172.2-2014 (Amdt 1 2018), and is valid until 10 July 2027; its listed products include the FI-20 wall hang pan, the FI-20 back to wall pan, the FI-20, the FI-05, the FI-05 back to wall pan and the FI-05 wall hang pan. For the USA and Canada, the manufacturer holds IAPMO R&T cUPC listings under File No. 6560 for ceramic plumbing fixtures (ASME A112.19.2-2024/CSA B45.1-24), File No. 6559 for water closets with a dual flush feature, and an EPA WaterSense listing, File No. 6561, for high-efficiency toilets. Production is covered by an ISO 9001:2015 quality management system certificate issued by the China Quality Certification Centre (CQC) for the production of sanitarywares.

Can a rimless wall-hung toilet be customized for an OEM or private-label programme?

Yes. Tangshan Houfengyuan Import and Export Co., Ltd offers both OEM and ODM production services, allowing clients to customize products according to their specifications. Available customization parameters include logo, colour, flush volume (1.28/1.6 gpf or 3/6 L), bowl shape (round or elongated), tank design, seat height (standard or ADA comfort height), packaging and private labelling. In-house R&D support covers more than 20 people, and the factory's adjustable tunnel-kiln firing curve allows production to be adjusted according to R&D needs.

What are the minimum order quantity, delivery terms and payment terms?

The stated purchasing terms are a minimum order quantity of 50 units, FOB delivery terms, 30/70 payment terms, and pre-shipment test as the acceptance criteria. Monthly production capacity is 290,000 units, which allows the same specification to be repeated across multiple phases of a project without re-engineering between orders.

How can a buyer validate the quality of a rimless washdown pan before committing to a full order?

Quality control is based on 100% inspection, with water testing performed on every piece, and the contractual acceptance criterion is a pre-shipment test. That means validation happens at two levels: individual piece testing before packing, and batch acceptance before shipment. Buyers specifying for hotel or apartment programmes can also review the model documentation — the WaterMark and cUPC listings and the ISO 9001:2015 certificate — as part of the same verification step. A full product brochure is available for download, and the sales team can be contacted directly for specification confirmation.

What is the production lead time for a rimless washdown wall-hung toilet order?

Quoted lead time is 35–45 days from order confirmation, supported by a monthly capacity of 290,000 units and a minimum order quantity of 50 units. Orders are supplied on FOB terms with 30/70 payment terms, and finished products carry a 3-year warranty. For project schedules, the 35–45 day window should be planned against the shipping transit time to the destination market rather than treated as a delivery date.

Conclusion

Rimless design and washdown flushing are engineering choices that change how a wall-hung toilet is cleaned, serviced and specified — not marketing labels. The FI-20 wall hang pan makes the specification concrete: a wall hung toilet with a rimless bowl, a washdown flushing system, a high-temperature fired ceramic body, and overall dimensions of 495 x 365 x 365 mm, listed under WaterMark Certificate of Conformity WMK26227 for the Australian market and supported by cUPC and EPA WaterSense listings for North America.

The decisions that determine whether a rimless washdown specification succeeds are made before the order: confirming the installation type and carrier position, locking the flush volume, verifying that the certificate names the exact model, defining the OEM requirements, and agreeing the pre-shipment acceptance criteria. Handled in that order, rimless washdown wall-hung toilets are a repeatable specification for hotel, apartment, wholesale and construction programmes — rather than a fixture that has to be re-engineered at every phase.