Best Water Heater 2019 – Buyers Guide

The cost of heating water can make up around 20% of your household budget, only just behind that of warming and cooling your home throughout the year. It is an important part of keeping everything flowing, and it is only when the hot water is gone that you realise how much you relied on it.

Water heaters are an alternative to fitting boilers to a central heating system. They can be a great way to get immediate hot water to sinks if you have no gas supply or want to run your home fully electric. They’re also perfect if you run a business from a set commercial location and need hot water for a canteen, bathroom or staff kitchen.

But where do you even start looking? Well, it is a good idea to get advice from a plumber to ensure your plans are enforceable and you have the cold water supply required. After this is done though, you’ll need to pick the best option for your needs. Take a look at our buying guide, and then see which water heaters we rate highly.

The Best Water Heater – Our Top Picks

IMAGE PRODUCT DETAILS
Ariston Andris Lux Under Sink Water Heater
  • Capacity: 15L
  • Power Output: 3kW
  • Dimensions: 36 x 36 x 32.7 cm
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Hyco Oversink 5 Litre Tank Handy Flow
  • Capacity: 5L
  • Power Output: 2kW
  • Dimensions: 45 x 28 x 18.6 cm
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Triton T30i 3kW Handwash
  • Flow Rate: 0.8L – 2L per min
  • Power Output: 3kW
  • Dimensions: 30.4 x 25.4 x 18 cm
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Best Under Sink Water Heater

Ariston Andris Lux Under Sink Water Heater

Packed full of handy little features, this Ariston model is as close to perfection as you can get with a water heater. No wonder it is a market leader.

First of all, there is a copper heating element inside the tank. This doesn’t only make warming up the water much quicker, but also helps to boost the purity of the water. The temperature dial is easily accessible on the front of the box, so you can adjust depending on whichever task you’re undertaking.

We loved the ‘E’ setting too, which stands for ‘Eco’. It optimises the temperature yet saves energy, so it will be cost-effective to run. Perfect both if you will be using it a lot, or there are long gaps between usage yet it still needs to tick over to keep warm.

It is modern and compact, and the inside of the tank is lined with a titanium enamelled heating element which helps prevent it from corroding. Heat up times are decent, at around 15 minutes for the 15L option.

We haven’t even mentioned this high capacity yet, which is ideal for anyone who needs a heater for a more demanding area. There is also a 10L and 30L option available, but we think the middle option will be perfectly sufficient for the majority of applications.

We like

  • Great capacity
  • Easy to control
  • Eco option
  • Price

We dislike

  • Check dimensions as it is a bit boxy and bulky

Final Verdict

Installation is easy, with instructions breaking it down into just ten easy to follow steps. To say it leads the way in so many areas, the price is very generous - an all-round winner

+ Specifications

  • Capacity: 15L
  • Power Output: 3kW
  • Dimensions: 36 x 36 x 32.7 cm

+ Downloads

Ariston Andris Lux Under Sink Water Heater User Manual

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ATC Under sink Water Heater

With polyurethane foam insulation to reduce heat loss and improve efficiency, this water heater is an ideal way to supply up to three sinks with hot water when there is only a cold supply.

As it will cope with several sinks, it would be great in an annexe or outhouse where there is a need for both a bathroom and kitchen sink. The powder porcelain enamel tank lining delivers twice the corrosion resistance of the usual glass linings, so there is no worry of it starting to wear away within a year of heavy usage.

We loved how it gets very hot very quickly. When the temperature dial is turned halfway, it is already too hot to comfortably wash hands, so the range is incredibly generous. Perfect if you’ll need to wash dishes or make hot drinks as well.

We will also say that it is important to properly work out how much water you will need from the tank at any one time. Due to the way that under sink storage tanks work, the 10-litre tank only really produces 5 litres of hot water before the rest becomes rather tepid. We found that if you need the full 10 litres, turn the temperature up high, so it balances out. It could be worth buying the size up for your needs.

As mentioned, it heats very quickly again. But the wait could become frustrating if you’re undertaking heavy tasks. The 5-litre option will allow you to fill a sink for washing dishes but not much more.

Overall though, it is a great option, and other reviewers say that all of their installations were seamless and went without any hitches.

We like

  • Great heat range
  • Can be connected up to multiple sinks
  • Good insulation

We dislike

  • Need to work around the amount of hot water you get

Final Verdict

A well-priced and reliable offering if you need something easy to use and set up, and the strong build means it will cope with your demands for years

+ Specifications

  • Capacity: 5/10/15 L
  • Power Output: 2kW
  • Dimensions: 24.6 x 27.3 x 41.5 cm (10L)

+ Downloads

ATC Under sink Water Heater User Manual

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Hyco Speedflow Undersink Electric 2kW Slim 5 Litre Tank

One of the more pleasant looking tanks on the market if that is important to you, this option from Hyco may be small, but it certainly competes with ones twice the size.

Great if you are placing in a room with no hot water system, water takes forever to reach your sink or want to go electric. This tank can be placed under any sink for low-demand hand washing or dishwashing purposes.

There is a temperature control dial so you can perfect it for the task at hand. A neon power light will let you know when its services are being used. It reaches a temperature up to 75 degrees, which is perfectly suitable for the vast majority of needs.

A 1.5m power cable is generous and comes pre-wired for easier installation. If you are rather knowledgeable regarding DIY and plumbing, you may even be able to give it a go yourself. Either mount it to a wall or leave it floor standing if it’s under a sink.

It is PX4 waterproof rated, and the inner is porcelain enamel-lined, so safe from corrosion and rust over time. You will be able to get around 2 L of hot water from it before it starts going tepid, and it takes about 12 minutes to fully heat again. Ideal for sinks or hand washing in lower demand areas, and it’ll also work with mixer taps.

We like

  • Easy to install
  • Looks modern
  • Built to last

We dislike

  • Slightly longer heat time than some other models

Final Verdict

A great price if you just need a smaller tank for occasional use, but it packs a punch with the temperature ability

+ Specifications

  • Capacity: 5L
  • Power Output: 2kW
  • Dimensions: 41.5 x 31.5 x 30 cm

+ Downloads

Hyco Speedflow Undersink Electric 2kW Slim 5 Litre Tank User Manual

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Best Over Sink Water Heater

Stiebel Eltron SN 5 SL GB Vented Oversink Water Heater

Combining the efficiency of storing hot water with the ease of an over sink hand wash design, this heater is perfect for areas which are in high-demand, such as bathrooms or food preparation kitchens for small businesses.

Temperature can be adjustable between 35 and 85 degrees, so a consistent flow of water is available at all times. A thermal cut out ability, which can be set at 38, 45, 55 or 65°C, makes it great if several different people will be using it, such as in a public setting.

To keep running costs low, there is highly effective thermal insulation in place. This keeps the heat inside the boiler, so none of the energy that went into the heating process was wasted. Standby consumption is low, and there is also an eco setting. This averages 60°C – seen as the ideal temperature for effective washing.

The latest ‘Drop Stop Function’ technology means that an expansion tank is not required. Any water expansion is taken up in the tank and not through the tap. This also means less heat is lost, water doesn’t drip and limescale won’t build up.

Because it is a tank model, once it has been emptied it takes a little while to refill and reheat. A full tank takes around 15 minutes, so it is best for an area which sees demand but not to the level where this hot water wouldn’t be able to replenish.

We like

  • Price
  • Good temperature control
  • Modern style

We dislike

  • Reheat waiting time

Final Verdict

Clean design, simple to use and perfect for those areas where a smaller hand wash heater just won’t do. The price is also incredibly generous

+ Specifications

  • Capacity: 5L
  • Power Output: 2kW
  • Dimensions: 26.3 x 42.1 x 23 cm

+ Downloads

Stiebel Eltron SN 5 SL GB Vented Oversink Water Heater User Manual

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Triton T30i 3kW Handwash

When only a cold water supply is given, the usability of a sink is suddenly reduced. It can’t be used for hand washing for one, which is not ideal if it is in a bathroom or kitchen environment.

This Triton over sink hand wash facility sorts that out. A single on/off and temperature control dial and 200mm swivel arm give a great amount of control to the user. It is compact, so if you want it to remain quite unobtrusive, it is an ideal model.

A standout selling point is the price. It might not be the absolute best heater in terms of power and water supply, but for the cost, it is a product which does the job. You can buy in bulk too, so if you need a couple of tanks as you want to kit out the whole home or have outside studios, you’re good to go.

As the temperature increases, the flow rate decreases slightly. It is still comfortable for washing hands, but if you need to fill buckets or sinks, then you may have to wait a little while. The additional shower head fitting gives more pressure, so it is best to always use it with this in place.

This is our only little issue though. Overall, for the price, you can’t really wish for more.

We like

  • Price
  • Dial is easy to turn and adjust

We dislike

  • Issues with pressure

Final Verdict

Best for washing hands, it is easy and clear to use and won’t look completely out of place either

+ Specifications

  • Flow Rate: 0.8L – 2L per min
  • Power Output: 3kW
  • Dimensions: 30.4 x 25.4 x 18 cm

+ Downloads

Triton T30i 3kW Handwash User Manual

Download

Hyco Oversink 5 Litre Tank Handy Flow

If you need a large amount of hot water frequently, such as in a workshop or food production environment, then an over sink tank which stores the water could be the best option.

It is lightweight and can be installed easily, which cuts a lot of the effort out. The overall size is relatively slimline and non-bulky too so that it won’t stand out too much.

As a point of use tank, it is best for hand or dishwashing at a single sink. Talking of garages and outbuildings, it doesn’t only monitor its internal temperature but also that of the external environment. A frost protection setting will ensure it still works well when the heat in the room dips, so you’ll still have perfectly hot water.

The 1m long power cable is pre-fitted to save time during installation, and a wall fixing bracket is included. A white corrosion-proof case will keep it looking as good as new for years to come. There’s also no need for an expansion vessel as it is all done automatically.

Because it is a tank, if you need to fill a bucket or sink it’s best to turn the temperature quite high. When the cooler water kicks in, it will still be hot overall. You also won’t get the full 5L capacity of hot water. But it likely won’t be too much of an issue for your needs.

We like

  • Cost
  • Heats water relatively quickly

We dislike

  • Quite dated design

Final Verdict

The perfect size for hand washing areas. Not the nicest to look at but comes in at a good price

+ Specifications

  • Capacity: 5L
  • Power Output: 2kW
  • Dimensions: 45 x 28 x 18.6 cm

+ Downloads

Hyco Oversink 5 Litre Tank Handy Flow User Manual

Download

Stiebel Eltron Handwash Water Heater

Working on demand to deliver hot water when required, this hand wash heater is compact and safe to use.

There is a temperature safety cut-out at 52⁰C, which resets when it is back to 42⁰C. If it is going to be used in an environment where several people will be using it, such as a bathroom of a workplace, this is ideal as it reduces the risk of accidents. The temperature stabiliser will ensure both the temperature and pressure remain consistent, too.

The dial is easy to turn too, which makes it good for multi-person use. Thanks to the large grip, people can adjust the settings to suit their own preferences, even with wet hands.

When the temperature is increased, the flow rate reduces slightly to allow this to be reached. It then increases when the heat is lowered if you need a bit more power. This does mean that at the hottest setting, it is more of a trickle than a jet of water, but it still does the job.

It won’t consume any energy when on standby, so is a cost-effective heater to run. It is also pretty budget friendly to purchase, so in all a great solution to your hot water woes.

We like

  • Safety cut out
  • Price
  • Dial easy to turn

We dislike

  • Despite being for safety, many competitors reach much higher temperatures

Final Verdict

Simple to use and featuring a basic design which can be accommodated anywhere. We liked the concealed connections at the bottom of the device for an even cleaner look

+ Specifications

  • Flow Rate: N/A Power
  • Output: 3kW
  • Dimensions: 8.5 x 23.5 x 15.1 cm

+ Downloads

Stiebel Eltron Handwash Water Heater User Manual

Download

Redring Manual I3V Manual Hand Wash

Thanks to the innovative Vortex technology, the flow rate from this water heater isn’t only improved, but the likelihood of limescale is reduced too. Perfect if you live in a hard water area.

Hard water can often be difficult to deal with using such products. The fact that this design has combated issues to a certain degree is welcomed. There is a single dial for the on/off function and temperature control, for easy use.

A sprinkler on the bottom of the arm is good for thorough hand washing. This can be removed if you prefer a steadier stream. Because there isn’t much power given out, it is best for hand washing as opposed to filling sinks or buckets.

There is a red power light which comes on when the heating elements are getting to work for safety. From the switched off position, you rotate the dial anti-clockwise to get the hot water first and then the cold. Hot water takes less than ten seconds to properly start emerging which is a good time.

The delivery tube is 8cm long which is generous and can be swivelled a full 360, degrees so the user has full control.

It needs to be hard wired as opposed to plugging it in so an electrician will need to be booked. The actual price of the heater is good though so this should balance out, and the instructions are easy to follow. Other reviews mention the fact that your home/building must have good water pressure to help it work at its optimum, however. So if this is for an outbuilding or basement area, you may have to reconsider. It also can’t be positioned in areas which may be affected by frost or low temperatures.

We like

  • Easy to operate
  • Good to install

We dislike

  • Design is a bit dated
  • Requires great water pressure levels

Final Verdict

A good price and easy to navigate. We have a few little issues, and it isn’t suitable for every home or building, but the price is still worth the purchase

+ Specifications

  • Flow Rate: N/A
  • Power Output: 3kW
  • Dimensions: 25.1 x 14.1 x 11.4 cm

+ Downloads

Redring Manual I3V Manual Hand Wash User Manual

Download

Help and Resources

Water Heater Buying Guide

Types Of Electric Water Heater

There are several different forms of water heater on the market, such as solar, storage tank and tankless. However the most common for kitchens  and bathrooms are:

  • Under Sink: Designed for areas where there is a cold water supply via a tap. The boiler allows for this to be turned into hot water as they warm then store the water ready for use rather than heating it on demand. Under sink options can usually cope with more demanding environments. Some may also be able to provide hot water to more than one sink.
  • Over Sink: Otherwise known as Point Of Use Water Heaters. They are designed to provide water to areas where a traditional tap and sink setup is not available, such as handwashing facilities which are a considerable distance from mains heating. They require a cold water pipe connection to run but work as a tankless heater to turn this into hot water. They can be placed pretty much anywhere, and usually feature temperature regulators for safety. Often limited on how much water per hour they can produce, and at which pressures.

Under sink options are usually best for kitchens where there may be a few different uses required, and over sink for bathrooms where needs are pretty limited to hand washing.

Capacity

All under sink and some over sink tanks store water, so you need to bear in mind how much they can store versus your demands. The hot water that you use is replaced by cold water straight away. This can then mix with the hot water.

The time it takes the cold water to heat can be anywhere from a few minutes to half an hour. If you’re in a demanding area, you will want to get a fine balance between enough water being produced and a good reheating time.

It is a general rule of thumb that you’ll get around half of the capacity of the tank in hot water before this starts to get tepid. Think about what you’ll be using it for, and how much you will need at any one time. Filling buckets to wash cars may take a little while, for instance.

Expansion Tank

Water expands as it heats up. Expansion tanks are designed to relieve the pressure on your plumbing system when a heater is working to warm up its contents.

When the water is heated, the excess has nowhere to go. Most homes have a closed water supply, so it cannot be pumped back into the system and instead will have to be removed into one of the expansion areas. If there is no tank present, it can cause dripping taps.

Some tanks do not require expansions as they can regulate themselves, but if yours does, it will have to be installed as extra. They are usually installed on the cold water line to capture the water before it gets into the heater.

The good news is that it reduces the likelihood your tap will drip, which improves the longevity of your heater and reduces limescale build up.

What Is The Difference Between A Boiler And A Water Heater?

Boilers are designed to provide warmth to your entire home. They heat radiators and other heat sources, as well as your water. This includes your shower, kitchen tap and bathroom taps.

Water tanks are a lot more targeted, however. They are designed to provide hot water to certain cold water taps or provide water to sink areas where there is little chance for a fitted tap. They don’t heat your home, and often only work with one singular tap as opposed to an entire room or floor in your house.

Over Sink Hand Wash Or Under Sink Storage Tank?

The former is the most cost-effective. They only charge you for the electricity and water used, as opposed to heating a large capacity water tank thoroughly then keeping it warm. They are also really the only solution if you currently don’t have a sink and tap setup, or connection to a hot water supply.

The latter can often produce larger quantities of water on demand, and at higher pressures which could be better for filling sinks or buckets. Think of the normal way in which you’d use a kitchen tap. As they’re under sink, they’re usually hidden. If you have a cold water tap in place, then it could be more cost effective to install one of these as opposed to a separate water outlet.

Can I Power A Shower On A Water Heater?

Not really. They don’t generally deliver enough power or water for a shower. Some tank models can be purchased with capacities up to 30L, but due to the way a tank works, you won’t get a very consistent temperature delivery.

Electric showers are available as separate purchases. Water heaters are really only designed for taps and sinks.

Which Brands Should I Look Out For?

Some of the leading electric water heater manufacturers are Ariston, Triton, Stiebel Eltron and Hyco. Other brands are Main, Crown, ATC and Redring.