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The world we live in today is incredibly fast-paced. Whenever we want something, we want it to happen as quickly as possible. We really can’t blame ourselves. The race which brought about the incredible need for speed started as soon as we invented the very first piece of technology. Considering that the whole point of it was to make things easier for humankind, it’s only natural that we started wanting more and more of it.

People want their questions answered as quickly as possible. For that reason, there are online customer care portals in many companies. Even in households, people want their coffee instantly, and, as such, there are instant coffee makers.

Finally, people want to be able to use hot water when they need it. To match that desire with a product, there is such a thing as an under sink water heater. In this guide, we will be teaching you all you need to know about these products and how to start using them in your bathroom or/and in your kitchen today.

Our Top Pick

Bosch Electric Mini-Tank Water Heater Tronic 3000 T 2.5-Gallon (ES2.5) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted
3,194 Reviews
Bosch Electric Mini-Tank Water Heater Tronic 3000 T 2.5-Gallon (ES2.5) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted
  • CONVENIENT HOT WATER HEATER: 2.5 gallon point-of-use mini-tank fits under your sink to provide hot water right where you need it. Thermal efficiency is 98%. Dimensions : 13.75 W x 13.75 H x 10.75 D Inches
  • LONG LASTING QUALITY: This electric water heater is easy to maintain and has premium glass-lined material for a long service life. (Amps 12A, Volts (VAC) 120)
  • INDEPENDENT INSTALLATION: 36-37" cord plugs into a 120 volt outlet for independent installation or in-line with a large hot water source
  • FAST RECOVERY RATE: Eliminates long waits for hot water at your sink, get on demand hot water at your every need (supplies up to 2 sinks at a time)
  • EASILY MOUNTED: Can be shelf, wall or floor mounted (bracket included); simply tap into the cold water line and install the water heater directly at the sink to provide hot water

One of the best under sink water heaters around is the Bosch ES4 Tronic 3000 T Electric Water Heater. Asides its 6.8GPH, it also has a few other perks you’re sure to find exciting. This product should give you the best value for your money.

What are the best under sink water heaters on the market?

When it comes to getting this product, there is a tendency to get confused. This is largely so because you have several things you have to consider before getting them. We understand this plight. We, too, have been in tight spots before making purchases in the past. As such, we have compiled a list of the best under sink water heaters for your kitchen. Without further ado, here they are:

1. Bosch ES4 Tronic 3000 T Electric Water Heater

The very first on our list comes from the Bosch brand. This model has a tank that can hold and heat up to two and a half gallons of water with an astounding thermal efficiency of about 98%. Alongside the glass-lined design, this product comes with a recovery rate of 6.8GPH that can help you supply up to two different sinks with hot water at a time. 

It is not a one-trick wonder as it can be used in three different dimensions. First, if you need a supplement for an existing water heater that’s too far away, this model comes in handy. Secondly, as expected, it can function easily as the only water heater for one of your sinks. Thirdly, if you have a tankless water heater, already that experiences cold water sandwiching, this product can help act as a buffer for it. 

It is an ideal choice for you if you need it in your apartment, basement, garage, pool house, etc. However, its excellence does not stop there. The small size of the product also makes it particularly useful in recreational vehicles, boats, etc. Dependent entirely on your choice, you can install this unit under the sink, on the floor, or on a shelf.

Product Specifications

  • Weight: 15.5 pounds
  • Dimensions: 13.8 x 10.8 x 13.8 inches
  • Size: 2.5 gallons
  • Color: White
  • Voltage: 120 volts
  • Wattage: 1440 watts

Pros (What we like)

  • The product is small, compact, space-efficient. Additionally, the size and weight make it less of a hassle to install. 
  • It has great thermal efficiency, which makes it unlikely to consume more energy than expected.
  • It has a recovery rate of about 6.8GPH, which means you’ll have to wait less before getting your water.
  • It has an astonishing warranty of six years on the unit itself and two years on the parts of the unit.
  • It allows you to install it in a variety of places.

Cons (What we don’t like)

  • It does not have quite as much space as you might need in its tank.

Final thoughts

This product is easy to use, install, and maintain. Asides these, it is quite efficient at its job. These factors alone, if you ask us, are great reasons you should consider getting this product. If you have relatively smaller needs than the average restaurant owner or a big family, it is an excellent choice for you.

2. Thermoflow UT10 Electric Mini-Tank Water Heater

Coming in hot at number two is the Thermoflow model. Besides its heating capabilities, it gives you about 2.6 gallons of tank space. In a situation where you aren’t quite in need of too much hot water, that tank capacity will serve you just right. Among others, it is a great idea for a doctor’s office, basement toilet, garage, kitchenette, small apartment, etc. 

With this model, you have the luxury of selecting between a mode that helps you save energy and another called frost protection mode, which makes it suitable for any season. You can choose a range of temperatures from 45ºF to 167ºF. One great thing about this model is its EPS foaming system, which allows you a reduction in standby time for hot water.

It is packed full of features. One of them is that it automatically cuts off power supply when needed. Basically, if you set a certain temperature, you do not have to worry about staying around to keep an eye on it. It does so for you. This will help prevent your heater from overheating. Also, it reduces the chances of damage to your product.

Asides that, the product design is such that you don’t have to expend so much effort in maintenance. Installation is as easy as plugging in the wire to a 120v outlet.

Product Specifications

  • Weight: 14.75 pounds
  • Dimensions: 18 x 11 x 12.2 inches
  • Size: 2.6 gallons
  • Color: White
  • Shape: Rectangular
  • Voltage: 120 volts
  • Installation method: Floor-mounted
  • Wattage: 1500 watts

Pros (What we like)

  • It is lightweight and does not occupy too much space.
  • It is very easy to install. You practically just need to plug it in.
  • It gives you as much water as you need in as little time as possible.
  • It comes with an auto turnoff feature for your protection.

Cons (What we don’t like)

  • It does not do very well in very cold areas.
  • It occupies a relatively significant amount of rectangular space

Final thoughts

This is another product that is worth a few extra bucks from your pocket. Asides the sleek design that really isn’t bad to look at, it offers you a range of features for effectiveness and user-friendliness. If you aren’t getting it for a commercial area where you’ll need a water heater a lot, this is the way to go.

3. Stiebel Eltron 233219 SHC Mini-Tank Water Heater

This sleek and elegantly designed German product assists you in getting hot water conveniently, quickly, and without wasting too much energy in the process. Whether you choose to keep it hidden or expose it to view, it serves you excellently in bathroom sinks, laundry areas, gas stations, food trucks, recreational vehicles, etc. 

It works with a standard 120-volt outlet and has a flatback, which means you won’t go through that much of a hassle fixing it onto your wall during installation. Asides the frost protection feature to maintain adequate temperatures within the tank, it provides you with another exciting feature – you can adjust the temperature with a thermostat dial on top of the product. The range is between 86ºF to 140ºF. It puts your hot water right where you need it, and this minimizes the number of pipe runs you will have to do. 

Product Specifications

  • Weight: 15.9 pounds
  • Dimensions: 11 x 10.6 x 18.7 inches
  • Size: 2.5 gallons
  • Style: SHC 2.5 
  • Color: White
  • Voltage: 110 volts

Pros (What we like)

  • It limits the pipe runs you’ll have to carry out.
  • It has a six-year warranty on its tank.

Cons (What we don’t like)

  • Its warranty only covers its tank.
  • Temperature range is comparatively limited

Final thoughts

Of the many different undersink water heaters that are out there, this one comes at number three on our list. It is only so because we believe that it can give you an effective and efficient service. It comes with the minimum tank capacity of two and a half gallons. This means that it is not in your best interest if you need a lot of water stored. However, when you put that aside, there aren’t a lot of reasons you shouldn’t invest in this.

4. InSkinErator HOT150 Instant Hot Water Dispenser

This is really more of a hot water dispenser than an under sink water heater. However, it still serves the same essential function of providing you with hot water when you need it. With a 750-watt tank for hot water, this model gives you instant gratification of your hot water needs. At virtually every point in time, the tank has steaming hot water for you to use conveniently with its faucet.

Separate from your faucet, it comes with its own. For your picking pleasure, it comes in five different styles. Each style helps complement your kitchen faucet and the elegant look of the place as well.

Asides that is that it has a system for filtering water. This is a pretty cool perk if you are the type to worry heavily about germs and hygiene. It has an adjustable thermostat with a pretty impressive range. Your options are between 160ºF and 210ºF.  

To top it all off, the model comes with a warranty that lasts for a year. During that year, if you face any problems, you don’t have to take the product to them. You simply contact them, and they come to you.

Product Specifications

  • Weight: 7 pounds
  • Dimensions: 5.4 x 2.8 x 6.2 inches
  • Size: 2/3 gallons
  • Style: Satin
  • Color: Satin Nickel
  • Material: Metal and plastic
  • Power source: Corded electric
  • Voltage: 115 volts
  • Wattage: 750 watts
  • Installation method: Deck-mounted

Pros (What we like)

  • It is incredibly light and compact.
  • Comes with a faucet
  • It has a one year warranty with home service.

Cons (What we don’t like)

  • The one year warranty is relatively shorter than some of its counterparts.

Final thoughts

While it defies the regular look of an under sink water heater, this product does well in providing excellent service. Besides that is the sleek design, which is sure to add to the beauty of your bathroom. If you’re big on aesthetics, this is a model that could be worth putting your money into. However, you might want to reconsider that just a bit if you are looking to store huge amounts of hot water for use in its sink.

5. Camplux ME25 Electric Water Heater

Our penultimate product, too, comes with quite a few tricks up its sleeves. With a small size and lightweight that very easily fits underneath your sink, this heater ensures that you have water right where it’s wanted. 

Its minimal storage of 2.5 gallons of water is just the right amount for you if you are looking to use it in a kitchenette, small bathroom, cabin, recreational vehicle, boat, etc. Additionally, this under sink hot water maker assists in your water conservation efforts by reducing the amount of time you have to wait for hot water to get to the faucet.

Some water heaters require you to spend quite an amount of money to recirculate water around the house for them to work. Contrastingly, Camplux ME25 merely requires you to tap into the water source for installation. It’s that simple. Afterward, you’ll plug it in and then use it for your hot water needs.

Its glass-lined tank and external dial allow for durability and easy temperature control, respectively. This 6.8 GPH model connects easily to a 120v outlet and gives a temperature range of 50°F to 140°F. 

Product Specifications

  • Weight: 17.2 pounds
  • Dimensions: 18.8 x 13.2 x 12.2 inches 
  • Size: 2.5 gallons
  • Power source: Corded electric
  • Voltage: 120 volts
  • Wattage: 1440 watts
  • Installation method: Wall/floor mounted

Pros (What we like)

  • It is water efficient.

Cons (What we don’t like)

  • It doesn’t have a warranty.

Final Thoughts 

It might have come in at the second to the last position on this list. However, there are hardly any reasons it can’t come in at the top position if you want to get an under sink water heater. Like most other product on this list, the water storage is only 2.5 gallons. That means it’s mostly suitable for smaller use. Additionally, it doesn’t come with a warranty, but it’s so well-designed and sturdy that you probably wouldn’t need one.

6. Ariston GL4S Mini-Tank Water Heater

This is the last, but certainly not the least on our list. One of its most attractive features, if you’re inclined in that direction, is its simple design. It adds no unnecessary excesses and merely sticks to what’s essential.

This four-gallon water heater is capable of providing you with hot water without any hard wiring. All you need to do is to plug it in, tap into the water supply, and there you go. The tank is glass-lined, which is a nice-to-have as it means your product will last longer. 

To top things off, it comes along with a limited one and six-year warranty for parts and the heat exchanger, respectively.

Product Specifications

  • Weight: 23.1 pounds
  • Dimensions: 13.8 x 13.5 x 13.8 inches 
  • Size: 4 gallons
  • Voltage: 120 volts
  • Wattage: 1500 watts

Pros (What we like)

  • It is water efficient.
  • Its four-gallon tank gives you more water.

Cons (What we don’t like)

  • It might take a bit more space than you have to spare.

Final Thoughts 

With this model, there is just about as much hot water as you need. Its four-gallon tank, as well as its effectiveness and warranties, make it the perfect choice for you.

Buyer’s Guide

What exactly are under sink water heaters?

In some families, there is that one water heater that serves the entire house. It supplies steaming hot water to the pipes in the home that need it and provides a certain level of luxury to its users. For the most part, it is an excellent fixture for your home as it does its job when required. 

However, there are a few downsides to it. If it is not as close to the bathroom as you need it to be, hot water will take longer to get to you. That means you will have to waste quality time waiting to get your needed serving of heated water. Additionally, there is also the chance that the general water heater might not be able to handle the number of demands your family makes on it. You can upgrade to a larger one, but that would be quite a hassle. 

At this point, an under sink water heater comes in handy to save you from all that stress and worry. This type of heater is a relatively small electrical unit that you fit under your bathroom or kitchen sink, and it is alternatively referred to as a point-of-use water heater.

Like virtually every water heater in existence, its sole purpose is to provide you with hot water. However, unlike some water heaters, it does not serve the whole house generally. Instead, it provides hot water to the faucet alone. 

In addition to giving you heated water just when you need it, it also helps you conserve energy. Due to their size as well as limited functions, it does not take quite as much electrical strength to power it as some other appliances in the average household. Its method of heating water entirely depends on the kind of heater it is.

What are the different types of under sink water heaters?

There are two major types of under sink water heaters. While they’re both efficient, there is the chance that you might prefer one over the other.

Tank water heater

The first variation of the undersink water heater is the one that comes along with a tank. These models can often hold between two and a half to a whopping seven gallons of water in their tank. When you turn them on, they heat your water for you, and the presence of that tank means you can keep it there for a while until you need it. This option is excellent because before you start cooking or doing those extra stubborn dishes, you can go to the kitchen a couple of minutes early and turn on the heater, so it starts its job, heating the water in the tank. Afterward, you go back to doing something else, and you can rest assured that when you need it, you can have it.

Additionally, with these models, you would become a bit more water-efficient. This is so because you would not have to keep your faucet running, waiting for hot water to get to you. Generally, these models are quite a breeze to install, and you can plug them in any outlet close by.

With this type of water heater, you do have to keep one thing in mind. Even though it can hold a significant amount of water in its reserves, your supply is still limited. As such, when you exhaust it, you will have to reheat another couple of gallons of water. Besides that, this kind of water heater makes for a great kitchen fixture.

Tankless water heater

A direct contrast to the one mentioned above, this under sink hot water heater does not have a tank where it stores water. Simply put, an under sink tankless water heater heats the water for you as soon as the water passes through the system. This option is great because as long as the faucet remains open, you can be sure that you will have hot water rushing for your use. 

In terms of energy, this model is an excellent choice. It is not constantly working to ensure that the water is hot. In the stead of working virtually every minute of the day to keep water heated, it has a detector which shows it when water is running in the faucet. Only then does it start to run. 

Additionally, this under sink instant hot water heater is often smaller and more compact than virtually all other water heaters. This is so because, it does not have a tank where it stores water. That is one less feature to increase its size for it to occupy space needlessly.

It is worthy of note that, unlike the tanked version, this under counter water heater might require a bit more time for installation. You have to be careful with the wiring and connection to existing pipes for it to work properly. However, after passing that stage, you know that you don’t have to worry about hot water anymore. When you want it, you can have it.

What are the things you should put into consideration before you get an under sink water heater?

The needs of individuals and families vary based on several peculiarities. What might work for one person might not necessarily work for another. In the same vein, what might pose a major concern for someone might just be a minor walk in the park for someone else. As such, there are no concrete universal laws you must follow if you wish to buy an under sink instant hot water maker. However, there are a couple of useful things that you might want to put some thought into before you invest your money into that cool looking water heater. They are:

The size

Like virtually every other product in existence, under sink water heaters come in different designs, and most importantly, in different sizes. Now, if you have a lot of space to spare, these sizes should really not be much of a problem for you. However, if the inverse is the case, then you might want to pay particular attention to the size of the unit you want to purchase. Take a good look at the dimensions before you choose to make that purchase so you won’t end up having issues fixing your point-of-use water heater under the sink.

Tank capacity

This part is specifically for you if you want a unit that comes with a tank. Most tanks in under sink water heaters range between 2.5 to 7 gallons in capacity. Some brands offer the luxury of giving you a variety of tank capacities per model. Others are a bit more frugal in that regard. As such, you should pay attention to how much water your heater can store relative to the amount of water you will be needing.

Energy efficiency

Generally, in the industry, point-of-use water heaters do not actually consume that much energy. As an environmentalist, you don’t have to have sleepless nights over whether or not you are doing the right thing for the environment. However, apart from their general energy efficient nature, there are some that cost even lower amounts of electricity than others. You might be concerned about how much power you are using, because of the environment or the bills you will have to pay. Either way, before making your purchase, you should definitely check how energy efficient your desired unit is.

Installation/maintenance efforts required

For the most part, under sink water heaters are relatively easy to install. For some units, you can merely plug into an outlet, and you’d be good to go. For some others, it might require a bit more technical know-how. As such, it will be wise if you take special care in checking the installation and maintenance requirements before you make your purchase. It will help you determine if you’ll need to set aside extra cost to hire a professional plumber or electrician to help with the installation just to be on the safe side.

Voltage and kilowatts

These two terms are related to electricity. However, they serve in different capacities. The voltage refers to the electrical requirement for powering the heater. In this regard, you’ll want to choose one that can be plugged conveniently into the outlet you have available. Most heaters can work with 120v outlets, and others are more inclined towards outlets with a voltage rating of 220. It is essential to choose one that suits what you have so you don’t end up blowing a fuse. Alternatively, you can change your outlet.

Kilowatt, on the other hand, refers to how much power the heater uses to heat water. The higher the KW, the larger the quantities of water your heater can handle at various speeds and vice versa. This, however, applies only to tankless units.

Rate of recovery 

In an under sink water heater, this term refers to the amount of water your unit can heat at a time. The unit of measurement for this is GPH (gallons per hour). Usually, one hour after you’ve emptied it, your unit should be able to raise the temperature by 90 degrees Fahrenheit. For example, if your unit is 5.7GPH, that means it should be able to heat 5.7 gallons of water to ninety degrees in one hour. So, the higher the rate of recovery, the less time it will take your unit to restore your hot water. This applies only to tank units.

Flow rate

The flow rate applies only to tankless units. However, they are similar to recovery rates in tank units. The measurement is in gallons per minute (GPM). If your flow rate is high, your under sink tankless water heater will be able to heat water faster and vice versa. So, if your desired unit comes at 2 GPM, that means you can be expecting about two gallons of water heated per minute. The general range for the flow rate is 0.5 – 2.25 GPM. If you run a restaurant and you get a lot of customers such that you will need huge amounts of hot water, this is particularly important. As such, you should pay critical attention to the amount of hot water you can get per minute. You wouldn’t want to delay your amazing customers.

Frequently Asked Questions (FAQs)

Q1: Are under sink water heaters reliable?

Yes, they are. This is even more so if you need to use hot water in just that spot. They’re sure to deliver when you need them to. 

Q2: What’s the maximum an under sink water heater warranty can last?

Most companies offer up to six years. Others that give more than that aren’t so common.

Q3: Do I need a plumber for installation? 

Not necessarily. Patiently reading the installation manual should do just the trick for you. However, if you don’t feel too comfortable getting it done yourself, you might want to get a plumber.

In conclusion 

The industry offers you many variations to choose from. That amount of choices can sometimes leave you paralyzed. Our guide merely makes it easier for you to make a choice. At this point, all that’s left to do is to pick up your phone/computer and place an order.

Last update on 2020-11-17 / Affiliate links / Images from Amazon Product Advertising API