As an Amazon Associate we earn from qualifying purchases. Learn More.

Choosing The Best Under Sink Water Heater

Woman washing hands in a bathroom sink

While there are many different types of water heaters on the market today, one option for you and your available space might be an under sink water heater. These are typically a type of small water heater for a compact space, they are energy-efficient, cost-effective, relatively easy to install, and provides fast water in just seconds. But first, let's define what exactly is an under sink water heater.

When choosing the best water heater for your home or commercial space, there are a ton of different factors that you should consider. But finding the right type for you doesn't need to be a headache or an overwhelming experience.

What is an Under Sink Heater?

An under sink water heater is a small and compact type of tankless water heater that gets its name because it can be easily fitted underneath a sink or basin in a bathroom or kitchen. They're also available in the more traditional tank-style design, and can be installed in any home, office, or building space as required. 

Because of its close proximity to the tap, an under sink water heater provides hot water within seconds of turning on the faucet. With a straight forward and energy efficient design, they are easy to use and install. Most even have a simple dial to change the water temperature.

Because of their small and compact size, tankless under sink water heaters are especially beneficial for those who live and/or work in smaller spaces. They are also a favorite for homeowners who live in cold climates, because they can deliver hot water quickly and efficiently.

Pressing benefit button

Benefits of a Tankless Under Sink Heater

Whether you've purchased a new home or you're currently doing renovations on your home or office bathroom, an under sink heater can add plenty of benefits to your space. Here are a few of our favorite benefits: 

Speedometer on fire

1. You'll Get Hot Water Faster

When you get an under sink heater, your hot water will be delivered fast, with no wait time and no wasted water. With the tankless water heater conveniently located under a sink, it can change the temperature of the water within seconds! You won't need to run the water for a minute or two waiting for your water to turn hot enough to do the dishes.

When running water for household tasks, especially cleaning, you often have to repeatedly turn the faucet on and off. This can be a nightmare if you have to wait for hot water each time!

Bosch Electric Mini-Tank Water Heater Tronic 3000 T 4-Gallon (ES4)  - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted

The Bosch Tronic 3000 Mini-Tank is a customer favorite, and has 3 tank sizes to choose between. Click here to learn more.

With an under sink water tank installed so close to a faucet, the very short distance between the water heater and the tap means you can immediately get hot water. You'll save both time and water doing household chores, especially during the coldest months of the year!

Hands holding a round glass full of water in the shape of the earth

2. You'll Save Gallons of Water

And speaking of saving water,  when you get your hot water immediately at the point of use, you'll no longer have to run the tap for a minute or two until the cold water turns hot. That means you'll end up saving gallons of water, which is better for the environment.

Water tap with a pipe full of money

3. Save Money

An under sink heater is not only beneficial for the environment, it's also great for your wallet! When you aren't waiting minutes for water to heat up, it means you aren't wasting water, which in turn means you're saving lots of money on your monthly water and electricity bills.

Ask around to see if anyone you know with a tankless water heater has saved bundles on their water bill. We bet they have!

Because under sink water heaters have an easy installation process, you shouldn't need to hire a costly professional to come to your house and take the entire day to install a massive water tank.

Bosch Electric Tankless Water Heater - Eliminate Time for Hot Water - Easy Installation

The Bosch Tronic 3000 Tankless Water Heater tucks nicely under a counter top and can be mounted either horizontally or vertically. It's available in 4 different sizes. Click here to learn more.

You'll also save a lot of extra piping and wiring since the water heater is so conveniently placed near your faucet. That  means you'll save bundles on pipe repairs, especially during the coldest months of the year. Overall, an under sink heater is a great financial investment for you and your home.

Lady washing hands in sink

4. An Under Sink Heater Takes Up Little Space

For all the benefits that an under sink heater offers, you might worry that it takes too much space in your bathroom or laundry room, especially if those spaces in your home, apartment studio space, or small business office are tight and compact.

The good news is that an under sink heater is also compact. As the name suggests, can easily fit under your sink, but it can also fit in your towel cabinet or discreetly mounted to the wall.

Stiebel Eltron 220817 5.7 kW, 240V Mini 6-2 Mini Single Handwashing Sink Tankless Electric Water Heater

The Stiebel Eltron Mini Tankless Water Heater is sleek and stylish. It's available in 4 different sizes. Click here to learn more.

Under kitchen counters, bathroom closets, or under the kitchen sink, this type of tankless water heater is small and compact so it won't get in the way or make your space look any less inviting as it can easily be hidden from view. Use our guide to find out what size tankless water heater you need for your home or workplace.

Wrench with bolt and nuts

5. Installation is Easy

Installing an under sink heater is relatively easy. You'll need to mount the heater in place, connect the hoses to the water supply, and then connect the electrical.

Manufacturers always include comprehensive instructions for their under sink water heaters, and many even provide step-by-step videos. In most cases you can install your new tankless water heater in as little as an hour

Many tank-style units can be plugged directly into a standard electrical outlet. Tankless models typically need to be hardwired, so if you're not comfortable working with electricity, you might want to call a professional.

Consult with a Local Plumber

Get FREE Quotes Today

Glasses sitting on top of paper with frequently asked questions

Frequently Asked Questions about Under Sink Water Heaters

Are Under Sink Water Heaters Good for Bathing?

While they are called under sink water heaters, they can also be installed anywhere you like. In the bathroom closet, in the cupboard, or even just mounted to a wall. This means that you can potentially use your water heater for hot water in the shower.

If you plan to use your small heater for a shower, it's important to find a unit that can provide the necessary water flow rate to service a shower. The average shower uses 2.5 gallons of water per minute, so you'll need an under sink tankless water heater with a flow rate of 2.5 gpm.

Or, if you prefer to purchase a tank-style heater, you'll need to consider the amount of time you spend in the shower. If you purchase a 10-gallon tank, you can expect to have hot water for at least 4-minutes.

Can Under Sink Water Heaters Be Used in Commercial Spaces?

Yes! These heaters aren't just for homes. If you work in an office, school, recreation center, or any other commercial space, this type of water heater might be the best option for you and your business. 

They are an excellent choice for a doctors office, wet bar, bathroom sink or an employee breakroom. Any place you need hot water, these small units will deliver.

How Far Away Can the Water Heater Be Placed From the Tap?

For the most immediate hot water, the closer the water heater is to the outlet the better. Placing your water heater more than six feet away from the sink will make it difficult for the heater to provide hot water.

If you're using the same tankless water heater for multiple taps that are a few feet apart, thus making its performance lag, consider purchasing a second one. They're generally inexpensive enough to have them installed at each sink, and they'll be able to provide better water pressure and a higher temperature for each faucet.

Stiebel Eltron 233219 2.5 gallon, 1300W, 120V SHC 2.5 Mini-Tank Electric Water Heater

The Stiebel Eltron Mini-Tank Water Heater is easy to install and plugs into a standard outlet. It's available in 2 different sizes. Click here to learn more.

How Difficult is the Installation Process?

Many homeowners can do the installation themselves. Each water heater comes with a set of instructions to help you get your unit up and running. Some manufacturers even provide videos to take you step-by-step through the set-up process.

Many tank-style units come with a power cord that can be plugged directly into a standard outlet. However, tankless models need to be hardwired, so if you're uncomfortable working with electricity, you can always hire a professional to install it for you. It won't take him long.

Consult with a Local Plumber

Get FREE Quotes Today

Can Under Sink Water Heaters Be Used in Cafes/Restaurants?

While most restaurants rely on instantaneous hot water every day, under sink water heaters might not be ideal because of the quantity required in a very short period of time.

These types of water heaters provide a lower flow rate than may be necessary for a fast-paced restaurant. While it's possible to install several under sink water heaters in a large commercial restaurant kitchen, it may not be ideal or even cost efficient.

However if you are running a small cafe with just one or two sinks, under sink water heaters are definitely an option. Before choosing you may want to speak with a plumber about which type of water tank would be best for your business needs.

Woman circling best on white board

When an Under Sink Water Heater is the Best Option for You

Obviously there are a lot of benefits with under sink water heaters, but you may still be unsure if it's the right appliance for you, your home, or your office. If you're still on the fence, here's a few other reasons why this type of water heater may be your best choice:

  • You Live in Cold Temperatures Most of the Year: When you're dependent on a large water tank that isn't close to your sink, you may have to wait thirty seconds to minutes in order to get hot water. Making sure you have immediate access to hot water is especially important in cold climates, because no one wants to run freezing cold water for a few minutes! With an under sink heater, you'll save money and water because you'll have hot water within seconds.
  • You Live in a Small, Compact Space: Many people are choosing to downsize on their home or apartment size and are living in smaller, more compact spaces. While this option is much more economical and practical than purchasing a massive home that requires tons of energy, it can sometimes also mean you have little space for all your needs. Even in the tightest of spaces, a compact and tankless water heater can conveniently fit under a sink, in a cupboard, or mounted to a wall.
  • You Want to be Energy-Friendly and Save Water: People are concerned with the amount of energy and resources they waste, and are choosing to be more eco savvy with their household needs. With an under sink heater, you'll be saving gallons of water because you won't have to wait at the faucet for up to several minutes to get hot water. You're not just getting a little luxury, you're also helping the environment.
  • You Want to Save Money: In addition to being more energy-efficient, many people are learning the benefits of penny pinching. If you're trying to budget, save, and make the most of your hard earned money, then an under sink heater might be the best option for you. Because you're saving so much water from running down the drain, you'll also be saving money on your water and electricity bills.
Blue swirl lines

The Bottom Line

As you can see above, there are many benefits to getting an under sink heater. Their efficiency and straight-forward technology allow them to deliver hot water the second you open a faucet, and they're relatively easy to install too!

Whether you live in a cold climate or simply want hot water delivered instantaneously, there are plenty of under sink heater options on the market today. But always make sure to do your research so you can find the right one to meet your needs.

It's a good idea to talk with a professional plumber to help you determine the right type of water heater that's right for you. They can help you find the right water flow rate, mounting location and plumbing and electrical options.

Consult with a Local Plumber

Get FREE Quotes Today