What Is A Tankless Toilet? | Pros, Cons & Considerations

If you have ever used a restroom in an airport, mall, or school you have likely used a tankless toilet! But what exactly is a tankless toilet and why would you want one?

In this post, I’ll explain what a tankless toilet is, how it works and go over its pros and cons as well as answer some popular questions about the topic.

Let’s dive in!

What Is A Tankless Toilet?

A tankless toilet does not use a traditional cistern (tank) to store enough water needed to flush the waste down the drain. Instead, it works using higher water pressure directly from a water supply line to wash the bowl clean each time. Forgoing the need for a cistern or toilet tank.
In many instances, a tankless toilet will use a pump housed in the unit to produce the needed water pressure. Since it has electricity run to the toilet for the pump, it may also have a bidet, heated seat, multiple flush options, lights, and even a self-cleaning option.

As the toilet does not have to wait to fill up a cistern, it is ready for the next visitor as soon as the bowl finishes filling. This is what made the design a popular choice for busy commercial locations like schools, transportation hubs, and large office buildings.

Tankless toilets are becoming a popular option in bathroom design as they break away from the need for a boxy tank that sticks out of the wall. With no tank behind the bowl, you can recover valuable square centimetres for a more spacious design. They reflect the decor of upscale hotels and distant cultures.

Tankless toilets have been around since the beginning of the 20th century, but they never really caught on in the residential market until the 2000s. Some high-rise flats incorporated tankless toilets in mid-century builds, but poor water pressure in cities often resulted in the compact toilet being replaced with a cistern model.

Wall hung tankless toilet
Wall-hung tankless toilet

How Does A Tankless Toilet Work?

Tankless toilets work much the same way as cistern-style toilets.

When you flush the toilet, a valve opens that introduces running water directly into the bowl at a pressure of 1.75 to 2.8 bars. Which is about twice the water pressure used in traditional units. The higher pressure is achieved by using larger water supply pipes in the home or a water pump housed in the base of the toilet.

It is much more common to find electric pump versions as changing out the size of water supply pipes to a residential home is exorbitant. If you live in a modern luxury flat, the building may have enough water pressure to install a flushometer tankless toilet, instead of one that uses a pump.

The high water pressure is jetted into the bowl at a precise angle that both washes down solids from the sides of the bowl and pushes the waste past the air trap and into the main waste pipe.

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Pros of a Tankless Toilet

  • Sleek modern style: A tankless toilet embraces the clean, crisp lines of contemporary decor. It fits right in with your floating vanity and standing soaker tub.

  • Less waiting between flushes: There is no need to wait for that big tank to fill up with water before trying again. Big families and households that entertain will enjoy less wait time at the door.

  • Comes with a variety of premium upgrades: Many tankless toilets take advantage of the need for electricity and add on bidets, lights, heat, and automatic cleaning cycles. This toilet belongs in your luxurious master en suite. 

  • Compact design: Since the tankless toilet needs fewer square centimetres of floor space, your bathroom will feel more spacious and welcoming. That is always a welcome improvement in many household bathrooms with less space.

Cons of a Tankless Toilet

  • Expensive upgrade: You will spend at least three times the cost of a standard toilet when you go tankless. And that does not include the added costs associated with updating your water supply or running new electrical into the bathroom.

  • Power outages are a problem: Since your tankless toilet uses a pump to increase its water pressure, when your power goes out, so does your toilet. The old-style toilet will keep operating as long as there is water pressure coming from the city. I guess you can just skip flushing until the lights come back on. Ew.

  • Repairs will be pricey: The parts and plumbers needed for traditional toilet fixes can be found in every store and village across the country. Your tankless toilet may demand a call to a speciality technician and replacement parts might need to be ordered.

How Much Does A Tankless Toilet Cost?

Adding a tankless toilet to your bathroom renovation will be a luxury upgrade. Traditional toilets are priced starting at just £250. The least expensive tankless model starts at around £800 and can climb into the thousands.

Since most tankless toilets designed for use in private homes require an electric pump to produce enough pressure, you will also be faced with higher installation costs. Any pump installed in a bathroom must meet British standards for safety.

Are Tankless Toilets More Efficient?

Since the introduction of water-saving toilets in the 1990s, most modern homes have a low-flow tank-style toilet that will use just 6 litres for each flush. Most tankless toilets meet these same standards for saving water. In fact, many may use less water. Some dual-flush tankless toilets are designed to use as little as 1.28 gallons (5.8L) per flush.

However, they usually require an electric pump to produce enough water pressure to clean the bowl with each flush, which ultimately means they use more resources for every visit to the loo.

Back-to-wall tankless toilet
Back-to-wall tankless toilet

Does A Tankless Toilet Need More Water Pressure?

It does depend on the model of tankless toilet that you purchase. A traditional tank-style toilet requires just .7 to 1 bar of water pressure to operate. Many versions of tankless toilets need 1.75 to 2.8 bars of pressure to effectively clean the bowl with every flush.

If your home does not have sufficient water pressure coming in from the city, your tankless toilet will feature a pump to increase pressure in the toilet.

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Are Tankless Toilets Worth it?

Tankless toilets are slowly growing in popularity. Their compact and space-saving design means they complement sleek and contemporary styles. The high water pressure can give a superior clean and means there’s no waiting between flushes.

However, you will be paying a premium for this type of toilet. And, depending on the model you install, it may need an electric pump. So, if the power ever goes out, it means you can’t use the toilet either.

Final Thoughts…

There you have it! Everything you need to know about tankless toilets!

Modern-looking, space-saving with quick flushes. A tankless toilet can be a stylish upgrade to your new small bathroom renovation. However, they come with a higher price tag and some installation considerations to think about.

So, will you go tankless with your new toilet?


Michael R

Michael is a KBB designer from the UK. He's been designing and project managing new Kitchen, Bedroom and Bathroom installations for over eight years now, and before that, he was an electrician and part of a KBB fitting team. He created The Bathroom Blueprint in early 2020.