Boiling Water Taps: A Buyer's Guide (Costs, Types, Installation & More)

3-in-1 domestic hot and cold instant 98°C boiling water in the colour gold.

Boiling water taps (also called 'instant hot water taps') are fast becoming the must-have appliance in British kitchens, offering next-level convenience for homeowners. If you're thinking of buying one for your kitchen, in this guide we hope to answer your most-asked questions about the costs, benefits and more.

What is a boiling water tap, and how do boiling water taps work?

A boiling water tap (sometimes called a '3-in-1' or '4-in-1' tap) offers instant boiling water at the turn of a handle. To do this, a boiler tank is fitted under your sink that maintains a supply of water at a boiling hot temperature, ready to be used whenever required.

The majority of boiling taps come with a filter for the boiling water, which removes impurities and carbon. The majority of boiling water taps will fit to your mains supply, giving you hot, cold and boiling water from a single spout, however, there are some models that only dispense boiling water, which means you will need to keep your mains-supplied tap for regular hot and cold.

Types of boiling water tap

There are generally four types of boiling water tap:

  • Boiling-only taps only dispense boiling water, which means you will need to keep your other tap for regular hot and cold water
  • 3-in-1 taps dispense regular hot and cold water, along with filtered boiling water
  • 4-in-1 taps dispense regular hot and cold water, filtered boiling water and filtered cold water
  • Flex taps can be 3-in-1 or 4-in-1, but they always have a pull-out spout

The benefits of boiling water taps

There's a reason for boiling water taps becoming as popular as they are:

  • They are incredibly convenient for everyday cooking and cleaning jobs, like brewing hot drinks, cooking pasta, noodles or vegetables, mopping your floors or filling up hot water bottles
  • They'll cut down on time wasted waiting for your pan or kettle to boil
  • They look great and are available in a wide range of finishes and styles, ideal for the vast majority of kitchen interiors
  • They are affordable to run and straightforward to install
  • You only use the boiling water you need, cutting down on the energy waste that comes with boiling a kettle

black kitchen cabinets and white worktops

How much does a boiling water tap cost?

Previously, a boiling water tap could cost upwards of £1,000+, depending on which brand and model you chose, and the upgrades you tagged on. While some taps can still cost upwards of £1,000, at Hot Water Taps, the price for our Avista 3-in-1 tap is just £299. This means it's more affordable than ever to own a boiling tap at home.

4-in-1 taps cost more than 3-in-1 taps, thanks to the cold water filter, while flex taps vary but are generally more costly than a basic 3-in-1 tap. If you need to hire a plumber to fit your tap, it may cost between £50 and £100, depending on the complexity of the job and tap model. We recommend you change your filter every 6 months to ensure it's running efficiently - ours cost just £29.95, though other brands may vary.

Running costs of a boiling water tap

Many people mistakenly assume a boiling water tap is expensive to run, but they are designed to run extremely efficiently.

An insulated boiler tank means minimal energy is required to maintain the water supply at a high temperature, costing between 10 and 15p a day. Comparatively, a kettle can cost anywhere from 2-6p to boil each time, depending on the make and the amount of water. This means that if you boil a kettle multiple times a day, you're unlikely to see much difference in your energy bills.

Boiling water taps - are they safe?

Parents might have concerns about whether a boiling water tap is safe to have around children. The truth is that brands have incorporated safety mechanisms into their taps, preventing the boiling water function from being accessed by children. Our taps have a spring-loaded mechanism which means the boiling function will turn off if not supervised, while the spout is insulated, preventing its surface from becoming too hot.

Kettles, on the other hand, can be dangerous if handled incorrectly. For example, an elderly person may drop or spill a kettle accidentally, or a child might tip the kettle over by mistake. Plus, water may splutter when coming out of the kettle's spout.

WRAS-approved products

To ensure your new tap has passed safety regulations, we recommend looking for WRAS-approved products. The Water Regulations Approval Scheme is an independent UK certification body, who independently test products like boiling water taps to ensure they're safe for the public.

Installing a boiling water tap

Installation is pretty straightforward, though sometimes a plumber is needed if you're inexperienced. To install a boiling water tap, you will need to fit the boiler tank and filter in your kitchen cabinet, requiring a plug socket and basic electrical and/or plumbing knowledge.

Boiler tanks

Boiler tanks range in size from 2 to 7 litres, so it's worth checking the dimensions to see how much space you have available in your cupboard. Our boiler tanks are 2.4 litres, dispensing 6-7 cups of instant boiling water a time. Because the tank only takes 4 minutes to reheat, it's not usually necessary to choose a bigger boiler tank than that.

Water pressure

The operating water pressure of our taps is between 0.5 to 5.0 bar, though this may vary for other brands, so bear this in mind before installation. If your water pressure is too low, you should speak to a plumber before ordering and installing your boiling water tap.


The process is generally hassle-free, and you are often covered by warranty should their be a defect with the product. We are proud to offer one of the longest warranties on the market, with 2 years for your tank and 5 years for your tap. It is important that you check the conditions for your warranty to ensure you meet any specific requirements, such as changing your filter regularly.

Maintaining an instant boiling water tap

Maintenance is pretty straightforward, requiring regular cleaning just like any other tap. This can be done with a gentle soapy mixture and doesn't require a special cleaner. As it's an electrical appliance, it should be inspected once a month for leaks or defects, particularly around the boiler tank and filter.

Should I turn my boiling water tap off at night?

We don't recommend turning your boiling water tap off at night, as it will consume more energy reheating than by simply leaving it on. If it will be unused for over a week (for example, if you are going away on holiday), you can switch it off at the socket to preserve energy, draining and refilling it when you return.

Do boiling water taps heat to 100°C?

Most taps on the market don't dispense 100°C, instead dispensing water that is a couple of degrees cooler. This accounts for heat loss when the water is ran through the spout. However, this makes little difference when it comes to cooking and cleaning; in fact many hot drinks like tea and coffee should be brewed below 100°C, and a cold steel saucepan will sap a few degrees of heat from boiling water on contact anyway.

Which boiling water tap should I buy?

We have four models, which each come with a variety of different spout styles and colours, including black, gold and copper. Our models are:

  • Avista - our most affordable 3-in-1 tap
  • Athena - our premium 3-in-1 tap
  • Quantum - our best-selling 4-in-1 tap
  • Platinum - our 4-in-1 tap with a pull-spout

Do you have any questions about instant hot water taps? Get in touch with our team to find out more.