Choosing the right toilet is an important part of designing a functional bathroom. Although it may not be the first feature you notice when entering a room, the toilet influences the overall layout, ease of cleaning, installation requirements and everyday comfort.
One decision homeowners increasingly encounter is whether to choose a traditional tank toilet or a tankless toilet. Both serve the same essential purpose, but they differ in how the flushing system is arranged, how much space the installation requires and the type of bathroom design they can support.
A traditional tank toilet stores water in a cistern before flushing. A tankless toilet, by contrast, operates without a conventional visible cistern attached to the toilet, although the precise flushing arrangement depends on the model. Some tankless designs rely on the available water supply and an integrated flushing mechanism, while other modern toilet installations use concealed cisterns that hide the tank behind a wall or furniture unit.
Understanding this distinction is important because a concealed cistern toilet and a genuinely tankless toilet are not necessarily the same thing.
In this guide, we explain the differences between tank and tankless toilets, compare their advantages and disadvantages, discuss water efficiency and maintenance, and explore how to choose the right option for your bathroom.
What Is a Tank Toilet?
A tank toilet is a conventional toilet that uses a cistern to store water for flushing. After the toilet is flushed, the cistern releases water into the bowl to remove waste. It then refills in preparation for the next flush.
The cistern is commonly positioned directly above or behind the toilet bowl, depending on the design. In many homes, this is the familiar floor-mounted toilet with a visible cistern connected to the pan.
Tank toilets are available in different configurations, including close-coupled toilets, single-piece toilets and certain back-to-wall arrangements. Their installation requirements vary according to the design.
How Does a Tank Toilet Work?
A tank toilet uses a flushing mechanism that releases stored water from the cistern into the bowl.
The process generally follows these steps:
- The flush mechanism is activated using a button, lever or another control.
- Water stored in the cistern flows into the toilet bowl.
- The flushing action carries waste through the toilet's waste outlet.
- The cistern begins refilling from the water supply.
- Once the cistern reaches the appropriate level, the filling mechanism stops the incoming water.
The exact arrangement depends on the toilet's design, but the underlying principle is the same: water is stored before it is released for flushing.
Many modern tank toilets use dual-flush mechanisms, allowing users to select between two flush volumes. The actual water consumption depends on the specific model and its flushing system.
What Are the Main Types of Tank Toilets?
Close-coupled toilets: The cistern sits directly on the toilet pan, creating a familiar, compact arrangement. This style is common in residential bathrooms and can be suitable for replacement projects where a conventional floor-mounted toilet is already installed.
Single-piece toilets: The pan and cistern are integrated into one overall unit. This creates a continuous appearance, although the cistern remains part of the toilet's design.
Back-to-wall toilets with concealed cisterns: The toilet pan sits on the floor while the cistern is hidden behind a suitable wall or furniture arrangement. The tank is still present, even though it is not visible.
The last distinction is particularly important when comparing tank and tankless toilets. A concealed cistern can make a bathroom look less cluttered, but it does not mean the toilet operates without a tank.
Explore the Jaquar UK toilet collection to compare different toilet styles and installation formats.
What Is a Tankless Toilet?
A tankless toilet is a toilet that operates without a conventional visible cistern attached to the toilet. Instead of relying on a separate, exposed tank that stores flushing water, the system uses a different flushing arrangement determined by its design.
Depending on the model, this may involve an integrated flushing mechanism and a direct connection to a suitable water supply. Some tankless toilets are designed as single-piece floor-mounted units, while others are wall-hung.
The absence of a conventional visible cistern gives tankless toilets a streamlined appearance, which can suit contemporary bathrooms where a clean, uncluttered design is preferred.
However, tankless toilets should not be confused with toilets that simply conceal their cistern behind a wall. A concealed-cistern toilet still stores water in a tank, whereas a genuinely tankless model does not use a conventional storage cistern in the same way.
How Does a Tankless Toilet Work?
A tankless toilet uses its designated flushing mechanism to deliver water to the bowl without relying on a conventional visible cistern attached to the pan.
The precise operation depends on the manufacturer's design. Water supply requirements, flushing technology and installation conditions can vary between models.
Before choosing a tankless toilet, it is important to establish whether the model requires a particular supply pressure, specialised plumbing connections or other installation provisions.
This is especially relevant when replacing an existing tank toilet. A tankless model should not be assumed to work with the existing plumbing simply because it fits within the available space.
What Are the Main Types of Tankless Toilets?
Tankless single-piece toilets: These have an integrated overall form and do not use a conventional exposed cistern. They can suit bathrooms where a continuous, streamlined appearance is desired.
Tankless wall-hung toilets: These are mounted above the floor and can create a floating appearance. The specific flushing system and installation requirements depend on the model.
Smart tankless toilets: Certain advanced WC designs combine tankless construction with electronic functions or integrated hygiene features. The available functions vary between products.
Jaquar UK offers selected tankless toilet options within its collection, including models from the Opal, Aria and Ornamix ranges. You can explore the Jaquar UK toilet collection to review available formats and individual product specifications.
Tank vs Tankless Toilet: Key Differences
Although tank and tankless toilets perform the same basic function, their installation and operation can differ significantly.
| Feature | Tank Toilet | Tankless Toilet |
|---|---|---|
| Flushing arrangement | Stores water in a cistern before flushing | Uses the model's tankless flushing mechanism without a conventional visible cistern attached to the toilet |
| Appearance | May have an exposed cistern or a concealed tank | Usually has a more streamlined appearance without a conventional visible cistern |
| Installation | Often straightforward when replacing a similar existing toilet | May require specific plumbing provisions and a compatible water supply |
| Space planning | An exposed cistern requires additional vertical space behind the pan | Removes the conventional visible cistern, but the complete installation dimensions still need checking |
| Water efficiency | Depends on the cistern, flush mechanism and flush volume | Depends on the flushing system, water supply and model specifications |
| Maintenance | Includes the cistern mechanism, pan and associated components | Depends on the integrated flushing mechanism and the manufacturer's maintenance requirements |
| Bathroom styles | Available in traditional and contemporary formats | Often chosen for modern and minimalist bathroom designs |
| Replacement suitability | Can be practical when the existing installation is compatible | Requires careful checks of water supply, waste connection and installation requirements |
| Initial cost | Varies by model and installation | Varies by model and installation, including any additional plumbing work |
The most important point is that tankless does not automatically mean more efficient, easier to install or cheaper to maintain. The individual model and the conditions in your bathroom determine how well the toilet will perform.
What Are the Advantages of a Tank Toilet?
Traditional tank toilets remain a practical choice for many homes because they offer a familiar design and a wide range of installation options.
1. Familiar and Straightforward Operation
Tank toilets use a well-established flushing arrangement. The cistern stores water and releases it when the flush mechanism is activated.
This familiar setup makes them a practical choice for many households, particularly when replacing an existing toilet with a similar model.
2. Flexible Product Choice
Tank toilets are available in a wide variety of shapes, sizes and configurations. You can choose from close-coupled, single-piece and concealed-cistern designs according to the bathroom layout.
This flexibility makes it easier to compare different appearances and installation approaches without necessarily changing the underlying plumbing arrangement.
3. Compatibility with Many Existing Bathrooms
When a home already has a conventional tank toilet, replacing it with a compatible model can often involve less alteration than introducing a different flushing system.
However, the waste outlet, pan dimensions, water connection and fixing positions must still be checked.
4. Dual-Flush Options
Many modern tank toilets incorporate dual-flush mechanisms. These allow the user to select a smaller or larger flush, depending on the toilet's design.
When used appropriately, a dual-flush system can help manage water consumption. The actual savings depend on the flush volumes, the toilet's performance and how it is used.
5. A Range of Installation Styles
Choosing a tank toilet does not mean you must accept a bulky appearance.
A concealed-cistern toilet can hide the tank behind a wall or furniture unit, creating a cleaner look while retaining the conventional cistern-based flushing arrangement.
Jaquar UK provides concealed cisterns and frames for compatible toilet installations. Always check the relevant product specifications to ensure that the cistern, frame and pan are suitable for one another.
What Are the Disadvantages of a Tank Toilet?
Despite their practicality, tank toilets have a few considerations worth keeping in mind.
1. Visible Cisterns Can Affect the Layout
A close-coupled toilet has a cistern positioned above or behind the pan. Depending on the room dimensions, this can influence how the toilet fits against a wall or beneath other features.
In a very compact bathroom, the overall projection and height of the toilet should be measured carefully.
2. The Cistern Requires Space
An exposed cistern occupies part of the visible space behind the toilet. Although this is rarely a problem in a larger bathroom, it may affect the proportions of a small cloakroom.
A concealed-cistern design can address the visual impact, but it requires a suitable installation arrangement and does not eliminate the tank itself.
3. Cistern Components Need Maintenance
A tank toilet contains components that control filling and flushing. Over time, these may require adjustment, repair or replacement.
For example, a faulty filling valve or flush mechanism may cause continuous running water or incomplete flushing. The specific repair depends on the component and the toilet design.
4. The Appearance May Not Suit Every Design
Some homeowners prefer the clean lines of a tankless toilet or a wall-hung WC. A conventional exposed cistern may not create the same visual effect.
However, the appearance of a bathroom depends on the complete arrangement of its fittings. A carefully chosen tank toilet can still work well in a contemporary space.
What Are the Advantages of a Tankless Toilet?
Tankless toilets appeal to homeowners who want a streamlined appearance and an alternative to the conventional cistern-based design.
1. A Cleaner, More Streamlined Appearance
Without a conventional visible cistern attached to the toilet, the WC can have a simpler overall profile.
This can work particularly well in modern bathrooms, where clean lines and uncluttered surfaces are important design considerations.
The overall appearance still depends on the toilet's shape, controls, pipework and installation arrangement.
2. Greater Design Flexibility
Tankless toilets are available in different formats, including selected single-piece and wall-hung designs.
This allows homeowners to consider a more contemporary toilet without being limited to one particular installation style.
The Jaquar UK Opal WC range includes tankless single-piece and tankless wall-hung options, alongside other toilet formats. Comparing the range can help you understand how different designs fit into your bathroom plans.
3. Reduced Visible Bulk
Removing the conventional visible cistern can make the toilet appear less bulky.
This may help create a more open visual arrangement, especially when the toilet is combined with a wall-hung installation and coordinated bathroom fittings.
However, the absence of a visible tank does not necessarily mean the complete installation occupies less space. The required plumbing connections, equipment and clearances still need to be considered.
4. A Contemporary Bathroom Feature
Tankless toilets can complement contemporary interiors that favour minimal detailing and integrated fittings.
They may be particularly suitable for homeowners planning a complete renovation and looking for a toilet that contributes to a consistent design throughout the room.
5. Options with Additional Features
Selected tankless and smart WC models incorporate additional technology, although the available features vary by product.
If you are considering a model with electronic functions, review its specifications carefully. Check the operating requirements, installation provisions, cleaning guidance and availability of servicing support before making a decision.
What Are the Disadvantages of a Tankless Toilet?
A tankless toilet can be an excellent fit for some bathrooms, but its installation requirements make it important to check suitability before buying.
1. Water Supply Compatibility Is Essential
Some tankless toilets depend on specific water supply conditions to operate as intended. The required pressure and connection arrangements vary by model.
If the existing plumbing does not meet the manufacturer's requirements, additional work may be necessary. A qualified installer should assess compatibility before the toilet is purchased.
2. Installation May Be More Involved
Replacing a tank toilet with a tankless model is not always a simple like-for-like change.
Depending on the system, the work may involve changes to the water supply, waste connection, electrical provision or other installation details.
The total cost should therefore include the toilet, any additional components and the labour required to prepare the bathroom.
3. The Initial Cost May Be Higher
The price of a tankless toilet depends on its design, technology and included features. Some models may require a larger initial investment than a conventional tank toilet.
However, it is not accurate to assume that every tankless model costs more than every tank toilet. Compare individual products and the complete installation cost rather than making a decision based on the category alone.
4. Maintenance Depends on the Specific System
A tankless toilet does not eliminate the need for maintenance. Its flushing mechanism and associated components must still be inspected and maintained according to the manufacturer's instructions.
If the model includes electronic features, servicing may require a technician familiar with that system.
Before buying, consider the maintenance guidance and the practicalities of obtaining support if a component needs attention.
5. Replacement Can Require More Planning
A tankless toilet may not be compatible with the existing plumbing arrangement of a home that currently uses a conventional cistern.
This does not make replacement impossible, but it does mean that the installation should be checked in advance. Confirm the model's requirements before removing the existing toilet.
Does a Tankless Toilet Save Water?
A tankless toilet does not automatically use less water than a tank toilet. Water consumption depends on the flushing system, the volume used per flush, the toilet's design and the conditions under which it operates.
A well-designed tank toilet with an appropriate dual-flush mechanism may use less water per flush than a particular tankless model. Equally, some tankless systems may offer efficient flushing performance when installed and operated according to their specifications.
If water efficiency is a priority, consider the following factors.
Check the manufacturer's flush specifications. Look for the stated water consumption and the flushing arrangements provided by the specific model.
Consider how the toilet will be used. Household size, frequency of use and flushing habits influence overall water consumption.
Ensure the system is correctly installed. The toilet must be compatible with the water supply and fitted according to the manufacturer's instructions.
Address leaks promptly. A toilet that continues to run after flushing can waste water regardless of whether it uses a tank.
Compare complete systems. If you are comparing two toilets, assess their specified performance rather than assuming that tankless technology is inherently more efficient.
A practical decision should be based on verified product information and the requirements of your household.
Which Toilet Is Better for a Small Bathroom?
In a small bathroom, the choice between a tank and tankless toilet should be guided by the available dimensions, the existing plumbing and the layout of the other fittings.
When a Tank Toilet Makes Sense
A conventional close-coupled toilet may be a practical option when replacing an existing floor-mounted model. If the waste outlet and water supply are compatible, the installation may require fewer alterations than changing to a different toilet system.
A compact tank toilet can also be suitable for a cloakroom, provided there is enough space for the complete unit and comfortable movement around it.
When a Tankless Toilet Makes Sense
A tankless toilet may suit a small bathroom where a streamlined appearance is a priority. Without a conventional visible cistern, the toilet can look less bulky.
However, the dimensions and installation requirements still need to be checked. A tankless model will not necessarily have a shorter projection than a compact tank toilet.
What About a Wall-Hung Toilet?
A wall-hung toilet is another option worth considering. The pan is suspended above the finished floor, and the cistern and supporting frame are concealed behind the wall or within a suitable installation arrangement.
This can make the floor underneath easier to access and create a visually open appearance.
However, a wall-hung toilet commonly uses a concealed cistern, so it should not automatically be classified as tankless. The tank may simply be hidden from view.
For more inspiration, read Jaquar UK's guide to small bathroom ideas.
Tankless Toilet vs Concealed Cistern Toilet: What Is the Difference?
These two terms are sometimes used interchangeably, but they describe different things.
A tankless toilet operates without a conventional storage cistern attached to the toilet, using the flushing arrangement specified for that model.
A concealed-cistern toilet still has a cistern, but the tank is hidden behind a wall, within a furniture unit or behind another suitable installation structure. The visible part of the installation may consist mainly of the toilet pan and flush plate.
A concealed-cistern arrangement can offer a streamlined appearance without requiring a tankless flushing system.
When choosing between them, consider whether your main priority is appearance, installation flexibility, water supply compatibility or the particular flushing technology.
Jaquar UK offers concealed cisterns and frames for compatible toilet installations. Review the product details to understand which WC formats and installation arrangements are supported.
How to Choose the Right Toilet for Your Home
The best toilet is the one that fits your bathroom, works with your plumbing and meets your practical requirements.
1. Assess the Existing Plumbing
Before selecting a toilet, check the water supply, waste outlet and installation arrangement.
If you are considering a tankless model, confirm the required water supply conditions with the manufacturer or installer. If you are choosing a concealed-cistern or wall-hung toilet, ensure the frame and cistern are compatible with the pan.
2. Measure the Available Space
Measure the width and projection of the area where the toilet will sit. Consider the distance to the basin, shower enclosure, furniture and door.
The toilet should fit comfortably without restricting access or making the bathroom difficult to use.
3. Decide on the Preferred Appearance
A close-coupled toilet may suit a familiar, practical layout. A single-piece or tankless design may be preferable if you want a more integrated appearance. A wall-hung or back-to-wall toilet can also create a streamlined effect, depending on the installation.
Consider how the toilet will look alongside your basin, taps and other bathroom fittings.
4. Compare the Total Installation Cost
The purchase price is only one part of the decision.
Include any required cistern, frame, flush plate, plumbing alterations, electrical work and installation labour. This is particularly important when moving from a conventional tank toilet to a different flushing system.
5. Consider Maintenance Requirements
Check how the toilet should be cleaned and whether any specialist maintenance is required.
For tank toilets, consider the accessibility of the cistern and its flushing components. For tankless models, review the maintenance requirements of the specific flushing mechanism and any electronic features.
6. Check the Product Specifications
Do not rely on the product category alone. Review the dimensions, installation instructions, flushing system, water requirements and included components.
If you are unsure whether a toilet will work with your bathroom, ask a qualified installer to assess the proposed installation before purchase.
Frequently Asked Questions About Tank and Tankless Toilets
1. What is the main difference between a tank and a tankless toilet?
A tank toilet stores water in a cistern before flushing. A tankless toilet operates without a conventional visible cistern attached to the WC and uses the flushing mechanism specified for that model. Their installation requirements and water supply arrangements can differ.
2. Is a tankless toilet better than a tank toilet?
Neither option is universally better. A tankless toilet may suit a bathroom where a streamlined appearance is important and the water supply meets the model's requirements. A tank toilet may be more practical when replacing an existing conventional toilet or when installation simplicity is a priority.
3. Does a tankless toilet use less water?
Not necessarily. Water consumption depends on the specific flushing system and its flush volume. Compare the manufacturer's specifications rather than assuming that a tankless design is automatically more water-efficient.
4. Is a tankless toilet more expensive to install?
It can be, particularly if the existing plumbing needs to be altered to meet the model's requirements. However, the total cost depends on the product and the installation. Obtain an itemised quotation before deciding.
5. Can I replace a tank toilet with a tankless toilet?
Potentially, yes, but compatibility must be confirmed. The water supply, waste connection, installation dimensions and any additional electrical or plumbing requirements should be checked before purchase.
6. Is a wall-hung toilet the same as a tankless toilet?
No. A wall-hung toilet describes how the pan is mounted, while tankless describes the flushing arrangement. Many wall-hung toilets use a concealed cistern, meaning the tank is hidden rather than eliminated.
7. What is the difference between a tankless toilet and a concealed-cistern toilet?
A concealed-cistern toilet still uses a tank, but the cistern is installed behind a wall or suitable furniture arrangement. A tankless toilet operates without a conventional storage cistern attached to the WC. The two designs can create a similar streamlined appearance but use different arrangements.
8. Are tank toilets difficult to maintain?
Tank toilets generally require routine cleaning and occasional attention to components such as the filling valve and flush mechanism. If the toilet develops a leak or continues running after flushing, the cause should be investigated and repaired.
9. Are tankless toilets suitable for small bathrooms?
They can be suitable, provided the model's dimensions and installation requirements work with the available space. A tankless toilet may have a streamlined appearance, but its actual projection and clearance requirements should be compared with other options.
10. Which toilet is best for a modern bathroom?
A tankless, wall-hung, back-to-wall or single-piece toilet can all suit a modern bathroom. The right choice depends on the room's proportions, plumbing, desired appearance and maintenance requirements. A concealed-cistern toilet is another option if you want a clean look while retaining a conventional cistern-based system.
Final Thoughts
The choice between a tank and tankless toilet comes down to how you want the bathroom to look, the flushing system you prefer and the practical requirements of your home.
A traditional tank toilet offers a familiar arrangement and a broad range of designs. It can be a sensible option for everyday use and may simplify replacement projects where the existing plumbing is compatible.
A tankless toilet offers an alternative to the conventional visible cistern and can complement contemporary bathroom interiors. However, its suitability depends on the specific model, water supply and installation requirements.
It is also important to distinguish tankless toilets from concealed-cistern toilets. Both can create a streamlined appearance, but a concealed-cistern system still contains a tank behind the wall or furniture.
Before making a decision, measure the available space, review the manufacturer's specifications and consider the complete installation cost. Explore the Jaquar UK toilet collection and concealed cistern and frame options to compare suitable configurations for your bathroom.
With careful planning, you can select a toilet that combines practical performance, straightforward maintenance and a design that complements the rest of your bathroom.
