Washdown vs Rimless Toilets: Flush and Cleaning Differences

What is a washdown toilet?

A washdown toilet uses a simple flush mechanism. The tank sits high or low, and when you flush, water pours directly from the tank into the bowl through a large opening. This creates a wave that pushes waste out through the trapway. Unlike siphonic toilets, which use a siphoning action to suck waste out, washdown models rely on the force of falling water.

According to the EPA, the average American family uses more than 300 gallons of water per day at home, so choosing an efficient flush system is important. Washdown toilets typically have a larger water surface area in the bowl, which can mean less splashing and a quieter flush in some cases. They are common in Europe and in compact or wall-hung designs. Because they have fewer internal passages, they can be easier to maintain, but they may use more water per flush if not designed efficiently. Always check the flush volume: look for models that meet WaterSense criteria, which require 1.28 gallons per flush or less.

For a deeper look at flush types, see our guide on siphonic vs washdown toilets.

What is a rimless toilet?

A rimless toilet has a bowl without the traditional inner rim that runs under the seat. In a standard toilet, the rim hides a series of small holes or jets that direct water into the bowl during a flush. A rimless design removes this rim entirely, leaving a smooth, continuous surface from the top of the bowl down to the water.

The main benefit is cleaning. Without a rim, there are no crevices for dirt, limescale, or bacteria to hide. You can wipe the entire interior of the bowl with a single stroke, and there are no hard-to-reach areas. This also improves hygiene, as there are fewer places for germs to accumulate. Rimless bowls are often paired with a direct or tornado-style flush that swirls water around the bowl to clean the surface.

For more on bowl design, see our article on toilet bowl rim design and cleanability.

How do they affect flushing performance?

Washdown flush performance depends on the water volume and the design of the trapway. Because it uses a direct push of water, it can be effective at moving waste, but it may not clean the bowl as thoroughly as a siphonic or rimless design that directs water around the entire surface. Some washdown models have a smaller water surface, which can lead to more splashing.

Rimless bowls are designed to work with specific flush systems. Many use a rimless or tornado flush that directs water from multiple jets around the bowl, creating a swirling action that cleans the sides. This can be more effective at removing waste and paper, but it requires a well-designed flush mechanism to be efficient. The EPA's WaterSense program certifies toilets that meet strict performance and efficiency criteria, so looking for that label ensures good performance regardless of the design.

The EPA notes that WaterSense labeled toilets must meet rigorous performance requirements, including bowl surface cleaning and waste extraction. So, when comparing models, look for that label to ensure good performance regardless of the design.

Cleaning and hygiene differences

The biggest difference is in cleaning. A rimless toilet is significantly easier to clean because there is no rim to scrub. You can reach every part of the bowl with a brush or cloth, and there are no hidden areas where grime can build up. This is a major advantage for households that want to minimize cleaning time or for those with mobility issues.

Washdown toilets, if they have a traditional rim, can be harder to clean. The rim and the jets underneath can accumulate limescale and bacteria, especially in areas with hard water. However, some washdown models are also rimless, combining the flush mechanism with a smooth bowl. In that case, you get the cleaning benefits of rimless with the flush characteristics of washdown.

For more on keeping your toilet clean, see our guide on how to clean toilet rim jets.

Which should you choose?

Your choice depends on your priorities. If easy cleaning and hygiene are your top concerns, a rimless toilet is the way to go. It is especially beneficial in bathrooms used by multiple people or in rental properties where cleanliness is a selling point. Rimless designs are common in modern and wall-hung toilets, so you have many style options.

If you are looking for a compact or wall-hung toilet, you may encounter washdown models. These are often space-saving and can be a good fit for small bathrooms. However, check the flush volume and performance. A washdown toilet with a WaterSense label will be efficient, but you may need to test it to see if it cleans to your satisfaction.

For most residential bathrooms, a rimless toilet with a siphonic or tornado flush is a solid choice. It offers good performance and easy maintenance. If you are considering a wall-hung model, see our wall-hung toilet buying guide.

Common misconceptions

One misconception is that washdown toilets are always less hygienic. That is not true. Hygiene depends on the bowl design and the flush system. A washdown toilet with a rimless bowl can be just as hygienic as a siphonic model. The key is to look for a smooth bowl without a rim.

Another misconception is that rimless toilets are weaker. In reality, rimless designs can be very effective if the flush mechanism is well-engineered. Many modern toilets use a rimless design with a powerful swirl flush that cleans the bowl thoroughly. Always check the flush performance, not just the design.

Finally, some people think that all wall-hung toilets are washdown. While many are, some use siphonic or pressure-assisted systems. Always read the specifications to know what you are getting.

What to pick for your use

Questions

Is a washdown toilet the same as a rimless toilet?

No. Washdown refers to the flush mechanism, while rimless refers to the bowl design. A toilet can be both washdown and rimless, or have one feature without the other.

Are rimless toilets more hygienic?

Yes, generally. Without a rim, there are fewer places for bacteria and grime to hide, making them easier to clean and more hygienic.

Do washdown toilets use more water?

Not necessarily. Many washdown toilets are designed to be water-efficient and meet WaterSense criteria of 1.28 gallons per flush or less. Always check the flush volume.

Can I retrofit a rimless bowl to my existing toilet?

No. The bowl design is part of the toilet's construction. You would need to replace the entire toilet to get a rimless design.