Which Boiling Water Tank Size Fits Your Kitchen?

A Practical Guide to Choosing the Right Boiling Water Tank for a Boiling Water Tap

Author: [2026-07-10] | By Xiamen Smart Water Technology Co., Ltd. Allen Huang  allen@kitchenwatertap.com

Choosing a boiling water tap is only half the decision. The boiling water tank underneath the sink determines how much hot water you can access, how quickly the system recovers, and how much cabinet space the installation requires.

For a small household, a compact 2.4L tank may be all you need. For a larger family, office, hospitality project, or high-use kitchen, moving up to a 4L, 5L, or even 8L tank can make more sense.

The key is not simply choosing the biggest tank available. It is choosing the capacity that matches actual water consumption, available cabinet space, recovery time, and installation requirements.

For kitchen brands, distributors, plumbing compani

es, water filtration companies, and private-label buyers, tank capacity is also an important product-development decision. The right under-sink boiling water tank can directly affect the user experience of your complete boiling water tap system.

Why Boiling Water Tank Size Matters

How Much Boiling Water Does a Kitchen Actually Need?

2.4L Boiling Water Tank

4L Boiling Water Tank

What About 3L, 5L, and 8L Tanks?

Boiling Water Tank Size Comparison

Temperature Control: Why 45–98°C Matters

How to Choose the Right Tank: A Simple Checklist

Does a Larger Tank Mean Higher Running Costs?

Why Filtration Matters in a Boiling Water Tap System

What B2B Buyers Should Consider Before Ordering

FAQs

Conclusion

Develop Your Own Boiling Water Tap System

A boiling water tap is designed to make everyday kitchen tasks easier. Instead of waiting for a kettle to boil, users can access hot filtered water directly from the tap.

But the tank underneath the counter has a very practical job: it stores and heats the water that supplies the boiling water tap.

If the tank is too small, users may need to wait for the system to recover during periods of heavy use. If it is unnecessarily large, it can consume valuable under-sink space and may add unnecessary cost and capacity.

That is why tank selection should start with real usage rather than simply choosing the largest available capacity.

For example:

• A couple making several cups of tea each day may be perfectly comfortable with a 2.4L tank.
• A family of four that regularly cooks with boiling water may prefer 4L.
• An office kitchen with continuous demand may need a larger configuration.
• A hospitality or commercial project may require a customized capacity based on peak consumption.

For an ODM boiling water tap manufacturer, offering multiple tank capacities also makes it easier to develop different product ranges for different markets.

There is no universal tank size that is perfect for every kitchen.

The better question is:

How much boiling water will the user need at one time, and how quickly does the tank need to recover?

Tea, coffee, cooking pasta, filling a saucepan, preparing baby food, and other kitchen tasks can all create different demand patterns.

A useful starting point is to look at:

This approach is particularly useful for boiling water tap distributors and private-label brands, because the same faucet can be paired with different tank capacities for different market segments.

For many residential kitchens, a 2.4L boiling water tank offers a practical balance between capacity and compact installation.

It is designed for everyday use without taking over the cabinet underneath the sink.

2.4L Tank Specifications

One of the most useful features is the 160mm width. Under-sink cabinets can become crowded very quickly once you add waste pipes, water filters, drainage components, and other equipment.

A narrower tank gives kitchen designers more freedom when planning the cabinet layout.

Who Is a 2.4L Tank Best For?

The 2.4L configuration is a good fit for:

• Couples and small families
• Apartments and compact kitchens
• Everyday tea and coffee preparation
• Users replacing a conventional kettle
• Kitchen renovation projects
• Residential boiling water tap systems
• Brands looking for a compact private-label solution

The tank can provide approximately 1.5L of water at 93°C in around 35 seconds, making it suitable for many everyday kitchen tasks.

For a typical home where several cups are prepared throughout the day rather than dozens of cups at once, this can be a very practical configuration.

If your customers regularly use more boiling water, a 4L boiling water tank provides additional capacity while remaining suitable for under-sink installation.

4L Tank Specifications

The 4L model can provide up to approximately 10 mugs' worth of boiling water, depending on mug size and how the water is used.

That makes it particularly useful for:

• Larger families
• Busy home kitchens
• Office kitchens
• Shared accommodation
• Hospitality applications
• High-volume tea and coffee preparation

If the typical customer regularly asks, "Can I have another cup?", moving from 2.4L to 4L can be a sensible product upgrade.

Not every application fits neatly into the 2.4L or 4L category.

For this reason, Xiamen Smart Water Technology offers a broader range of under-sink boiling water tanks, including:

2.4L, 3L, 4L, 5L, and 8L configurations.

The company also supports customization of tank capacity and functions for OEM and ODM projects.

This is particularly valuable for international buyers because product requirements can vary significantly between markets.

A compact apartment product may prioritize cabinet space, while a hospitality or commercial product may prioritize higher capacity.

Rather than forcing every customer into the same tank configuration, an OEM/ODM manufacturer can develop the tank around the intended application.

Available Capacity Range

The exact dimensions, heating performance, electrical configuration, temperature settings, and other specifications should be confirmed according to the selected model.

If you're comparing boiling water tap systems, capacity is only one part of the decision.

The table is intended as a practical starting point. Actual system performance depends on the complete boiling water tap system, incoming water temperature, electrical configuration, temperature setting, flow rate, and usage pattern.

A boiling water tap does not always need to dispense water at 100°C.

Different beverages and kitchen applications can benefit from different temperatures.

For example, delicate green tea is generally brewed below boiling temperature, while black tea and many cooking applications can use significantly hotter water.

Applicable Xiamen Smart Water Tech tank models use touchscreen temperature adjustment from approximately 45°C to 98°C, 14 preset temperature settings:45, 55, 65, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96 or 98 degrees, the thermostat is accurate within 0.5 degrees.

Temperature Range at a Glance

The ability to adjust temperature gives a 5-in-1 boiling water tap or multifunctional drinking water system more flexibility than a conventional kettle that simply boils water.

For private-label brands, adjustable temperature control can also become a useful product feature when positioning a premium kitchen tap.

1. Count Your Cups-Honestly

Start with actual usage rather than an idealized estimate.

If a household normally prepares fewer than six large mugs of boiling water at a time, the 2.4L configuration may be sufficient for everyday use.

If the kitchen regularly serves a larger group, consider 4L or above.

2. Measure the Cabinet

Before selecting a tank, measure the available space under the sink.

Don't forget to account for:

• Drain pipes
• Water filtration cartridges
• Waste disposal equipment
• Plumbing connections
• Electrical outlets
• Cabinet doors
• Service access

A tank may physically fit while still making maintenance unnecessarily difficult.

3. Think About Peak Usage

Daily consumption and peak consumption are not the same thing.

A household may use only several litres of boiling water across an entire day but need a larger amount during breakfast, dinner preparation, or weekend entertaining.

For B2B projects, peak demand is especially important.

4. Consider Recovery Time

A larger tank is not automatically better if the system takes significantly longer to recover.

The objective is to balance:

Capacity + recovery time + cabinet space + actual demand.

The 2.4L and 4L configurations described here have an approximate 4-minute reheat time under the stated product conditions.

5. Don't Forget Filtration

A boiling water tap system normally works together with water filtration.

The tank and faucet should therefore be considered as part of a complete system rather than as isolated components.

Depending on the product configuration, filtration may be integrated into the tank or supplied as part of the broader under-sink water system.

Not necessarily.

The energy required depends on factors such as:

• Amount of water heated
• Incoming water temperature
• Target temperature
• Tank insulation
• Heating efficiency
• Frequency of use
• Standby behavior

A larger tank stores more water, but that does not mean users will automatically consume more energy.

For product development, the more useful question is:

How much water does the customer actually need, and how often will the system reheat?

This is one reason why a compact 2.4L tank can be an attractive option for residential applications.

For a complete drinking-water solution, the boiling water tank should not be viewed separately from the filtration system.

Filtered water can improve taste and help reduce unwanted substances depending on the filtration technology selected.

A typical under-sink system may combine:

Water supply → filtration → boiler tank → boiling water tap

Some systems can also combine chilled, filtered, domestic hot, and domestic cold water in a multifunctional kitchen faucet.

For international brands developing a 5-in-1 boiling water tap, this system approach can simplify product positioning and create a more complete kitchen water solution.

For importers, distributors, kitchen brands, plumbing companies, water filtration companies, appliance brands, hospitality suppliers, property developers, kitchen manufacturers, wholesalers, and private-label buyers, tank capacity should be evaluated alongside the complete product specification.

Key OEM/ODM Evaluation Points

Xiamen Smart Water Technology focuses on OEM and ODM manufacturing for international drinking water system brands, allowing buyers to develop products around their market requirements rather than simply selecting an off-the-shelf configuration.

Is a 2.4L boiling water tank enough for a family?

For many small households, yes. A 2.4L tank is designed as a compact everyday solution and can provide approximately 1.5L of water at 93°C in around 35 seconds under the stated conditions. Larger households with heavier peak usage may prefer a 4L or larger configuration.

Is a 4L boiling water tank better than a 2.4L tank?

Not automatically. A 4L tank provides greater capacity, but it also requires more cabinet space. The better option depends on household size, peak demand, available installation space, and the intended application.

What boiling water tank sizes are available?

Xiamen Smart Water Technology currently offers 2.4L, 3L, 4L, 5L, and 8L tank configurations, with customization available for OEM and ODM projects.

Can the boiling water tank be customized?

Yes. Tank capacity and functions can be customized according to project requirements. International buyers should discuss dimensions, electrical specifications, heating performance, temperature control, filtration, faucet compatibility, and target-market requirements with the manufacturer.

How long does a boiling water tank take to reheat?

The 2.4L and 4L configurations described in this guide have an approximate reheating time of 4 minutes. Actual recovery performance can vary according to operating conditions and the specific configuration.

What temperature can the boiling water tank produce?

Applicable models support adjustable temperatures from approximately 75°C to 98°C through touchscreen controls. The exact temperature range depends on the selected model.

Can I use a boiling water tank with a 5-in-1 kitchen faucet?

Yes, when the faucet and tank are designed as a compatible system. A 5-in-1 kitchen faucet can combine functions such as standard hot and cold water with filtered boiling, chilled, or other drinking-water functions depending on the configuration.

Does a larger boiling water tank use more electricity?

Tank size alone does not determine energy consumption. Actual energy use depends on the amount of water heated, target temperature, incoming water temperature, insulation, heating efficiency, and usage frequency.

Does the tank include filtration?

Applicable Xiamen Smart Water Tech boiling water tap systems include filtration configurations. The exact filter arrangement depends on the selected product and system design.

Is an under-sink boiling water tank difficult to install?

Installation depends on the existing plumbing, electrical supply, cabinet layout, faucet configuration, and local requirements. Before installation, the available cabinet dimensions and service access should be checked carefully.

The best boiling water tank is not necessarily the biggest one.

For a compact residential kitchen, a 2.4L under-sink boiler tank can provide a strong balance between capacity, recovery time, and cabinet space. For larger households, offices, and higher-demand applications, a 4L tank may be more appropriate. For commercial, hospitality, or specialized projects, 5L, 8L, or customized capacities can provide additional flexibility.

The important thing is to look at the complete system:

Tank capacity + heating performance + recovery time + temperature control + filtration + faucet + installation space.

For brands developing a boiling water tap, this system-level approach can also make the difference between a product that simply works and one that customers genuinely enjoy using every day.

Xiamen Smart Water Technology Co., Ltd. is an experienced boiling water tap manufacturer and ODM partner serving international drinking water system brands.

The company offers multiple under-sink boiler capacities, including 2.4L, 3L, 4L, 5L, and 8L, with OEM/ODM customization available for different kitchen layouts, market requirements, and product positioning.

We work with:

• Importers
• Distributors
• Kitchen brands
• Plumbing companies
• Water filtration companies
• Appliance brands
• Hospitality suppliers
• Property developers
• Kitchen manufacturers
• Wholesalers
• Private-label buyers

If you are developing a new boiling water tap, replacing an existing boiler supplier, or looking for a customized under-sink boiling water tank, share your target market, preferred capacity, faucet configuration, and estimated order volume with our team.

Let's develop a boiling water tap system that fits your market-not just your cabinet.

Contact now