• Home
  • |
  • Blog
  • |
  • Water Heater Boosters: What You Should Know

Water Heater Boosters: What You Should Know


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

Sometimes we need a long hot shower to wash away a bad day. One thing that can make that bad day worse is running out of hot water too soon. Whether your hot water tank is too small, you're entertaining too many guests, your family is getting bigger, or you simply need more hot water, a water heater booster might be the economical solution to solve the problem.

This article will give you everything you need to know about water heater boosters. We'll explain why they may be the right answer for you, how to install them, and even give you a few popular choices to help you get started.

What is a Water Heater Booster?

A water heater booster is also known as a tank booster or a hot water heater booster, and it's an electronic device that attaches to your pre-existing electric or gas hot water heater.

These hot water boosters operate similarly to a tankless water heater in that they heat the water on the fly. However they differ from a tankless water heater in that a tankless water heater is a hot water tank replacement, whereas a water heater booster is a supplement. 

Once the hot water temperature drops during usage, the tank booster will activate and boost the heat to the desired temperature.

Some hot water boosters extend your hot water capacity by up to 71%. Better yet, these devices speed up the hot water recovery time. In fact, some models boast up to 385% faster water heat recovery! Not only can you enjoy a long hot shower, but another member of your household will also be able to enjoy a long hot shower in a fraction of the time usually required to replenish the tank.

Water heater boosters are small, affordable, and energy-efficient. They're the perfect solution for any household that needs more hot water than their current water heater can deliver. And the best part is, you won't need to replace your water heater.

Watch the Video

Why Do You Run Out of Hot Water?

Whether your hot water heater has a 30-gallon tank or an 80-gallon tank, they function the same. When you open a hot water faucet, hot water is pushed from the water tank and into the hot water-supply line. As hot water leaves the tank, the tank is refilled with cold water from the cold-water supply line.

As the cold water enters the tank it is mixed with the hot water, which gradually lowers the temperature. You may notice the temperature drop over extended hot water use. After running the hot water long enough, the hot water tank will become filled with lukewarm or even cold water.

Gas water heaters may take 30-minutes to an hour to regain the appropriate temperature, and electric water heaters often take twice as long.

This means that while your hot water heater may have a 50-gallon capacity, it doesn't mean that you can use 50-gallons of hot water in one session. Adding a water heater booster will prolong hot water usage, and many water heater booster users claim that they haven't run out of hot water since their upgrade.

Warm water splashing in hands

Benefits of a Water Heater Booster

As previously discussed, water heater boosters can increase the amount of hot water available by up to 71%, and some models even claim higher increases. But if having more available hot water isn't enough, there's even more benefits in installing a water heater booster. They can also:

Save Energy - Many boosters offer different usage modes that can lower your utility bills. For example, you can activate Vacation Mode or Eco Mode, which switches off the power to the tank when you don't need hot water.

Save Space - Hot water heater tanks require room. Some designated spaces are too tight for a larger tank. Water boosters are small additions to the water heater and need very little room. You'll be able to increase the available hot water without requiring as much space as a larger heater requires.

Save Money - Water heaters aren't cheap. The bigger the tank, the more expensive they tend to be. Installing a water heater booster is an economical solution to meet your families growing hot water needs, without breaking the bank.

Easy Installation - Replacing a hot water heater can be a challenging and time-consuming job. However, water heater boosters are designed with easy installation in mind. They often use the same power supply as the hot water tank and they come with the necessary cables to power both devices. With some plumbing and electrical skills, you should be able to install a water heater booster in less than an hour.

Freeze Protection - Some water heater boosters automatically power the tank when the thermistor senses dangerously low water temperatures. This function protects your water heater while conserving energy.

Scold-Protection - Set the maximum hot water temperature, and you won't need to worry about the kids burning themselves when running the hot water faucet.

Woman taking a hot shower

Do Water Heater Boosters Really Work?

Yes! Water heater boosters are a reliable and affordable device that will extend the usage of your hot water tank capacity. A quick internet search will provide numerous 5-star reviews from verified and satisfied customers. A water heater booster is the real deal and is the perfect solution for anyone who needs more hot water.

Who Can Benefit from a Water Heater Booster?

There are many benefits to using a water heater booster. If any of these situations sound familiar, then you may benefit from adding a water heater booster to your hot water system:

  • Anyone unsatisfied with their hot water capacity.
  • Growing families.
  • Households who plan to add or have added devices that use hot water, such as dishwashers.
  • Families who want to save money on utilities without the excessive spending of a tankless water heater install.
  • Households with concerns regarding scalding and hot water burns.
  • Anyone who hosts family and/or guest events.
Woman take a hot bath

Choosing a Water Heater Booster

Most people are unfamiliar with water heater boosters, so when selecting a booster, there are a few things you should consider. Whatever you choose, we advise you to take some time to think about the following:

Installation Process - Some boosters are designed for an easier installation, while other boosters favor power and efficiency. 

Power Capacity - For example, the Stiebel Eltron MegaBoost draws 40 amps and requires a 40 A circuit breaker. It'll need to be hardwired separately into its own 240-volt electrical circuit. On the other hand, the Rheem Water Heater Booster uses the power already supplied to your pre-existing hot water heater.

Energy Consumption - A hot water booster that performs better will typically require more energy, which will increase the cost of usage.

Warranty - Although more affordable than a new hot water heater, water heater boosters still cost money! Many brands offer a 5-year warranty, while others provide a 7-year warranty or more. If everything else is equal, choose the one with the better warranty.

Tool Belt

How to Install a Water Heater Booster

If you're comfortable doing DIY projects, you can probably handle installing a water heater booster yourself. But keep in mind you'll be working with electricity and plumbing, so it's important to do it right. Also, each manufacturer may have different instructions on how to install a water booster, this makes your best resource the manufacturer's installation guide.

The instructions below cover how to install a Rheem Water Heater Booster, which may be different from the one you've purchased. These instructions are intended to provide a general idea of the water heater booster's installation process.


Step 1 - Prepare

  • Confirm the contents of the box. Generally speaking, you should expect the hot water booster, the necessary wires, warranty information, a registration card, an installation manual, and a stop sheet.
  • Gather the needed tools. You may need screwdrivers, Teflon tape, a tape measure or ruler, needle nose pliers, an adjustable wrench, a pipe cutter, and a pencil or marker.
  • Confirm the needed clearance for the booster.
  • Shut off the power on the circuit breaker.
  • Shutoff the water supply to the water heater.
  • Connect a hose from the water heater drain valve to a nearby drain and open the drain valve.
  • Open all the hot water faucets in the house.
  • Cut the hot water outlet pipe as directed.


Step 2 - Installation and Plumbing

  • Connect the hot water outlet on the tank to the female NPT on the water heater booster's bottom side.
  • Connect the hot water copper line to the outlet thread on the unit's top side.
  • Secure the booster in place.
  • Close the tank drain valve.
  • Make sure at least one hot water faucet in the house is turned on.
  • Reopen the water supply valve on the cold inlet pipe.
  • Open all hot water faucets in the house to purge the air from the hot water lines. Failing to do this can cause damage to the booster.
  • Allow hot water to run through the lines for 2-3 minutes.


Step 3 - Electrical Installation 

  • Confirm the power at the circuit breaker is turned off.
  • Remove the wires from the existing water heater tank coming from the circuit breaker. Dependent on heater booster purchased.
  • Feed these wires through the backplate of the water heater booster.
  • Connect the wires from the circuit breaker to L1/L2/Ground on the booster.
  • Connect the supplied pig-tail cord to the booster T1/T2/Ground, and connect the other side to the tank.
  • Doublecheck all the wires, confirming they are tight and secure.
  • Turn on the power. Allow the water to heat and enjoy more hot water!

Watch the Video

Water Heater Booster Choices

The choices below are some of the popular options available, although it's worth noting that this segment of the industry is rapidly growing in popularity. It's important to do your research to ensure you find a water heater booster that meets your specific needs.

EcoSmart SmartBoost

The EcoSmart SmartBoost is a 7.2kW tank water heater booster that increases your hot water tank's efficiency and performance by up to 45%. This device installs onto a gas or electric hot water tank and can be mounted to a nearby wall.

It provides more hot water, optimizes the hot water system, and only activates when needed. In addition, it has a vacation mode to save you money while you're away. It saves money on energy, is easy to install and comes with everything you need to nearly double your hot water capacity.

EcoSmart ECOTB240 SmartBoost, white

EcoSmart SmartBoost

Rheem Water Heater Booster

Like the SmartBoost, the Rheem Water Heater Booster is a small device that is simple to install and amps up your water heater's performance by up to 45%. A Rheem Water Heater Booster, combined with a 50-gallon hot water heater will allow for the same hot water usage as an 80-gallon hot water tank. At a fraction of the cost of upgrading to a larger hot water heater, the Rheem Water Heater Booster is the perfect solution when you need to increase hot water output.

Rheem RTEX-AB Water Heater Booster

Rheem Water Heater Booster

Eemax Auto Booster

Rheem acquired Emax (which already owned EcoSmart) in 2015, so it's no surprise that the Eemax Auto Booster boasts the same abilities as the models previously mentioned. Whichever model you choose, you can expect 45% more hot water and more energy efficiency. The eEmax Auto Booster is an excellent solution for any home that has an inadequate hot water supply.

Eemax HATB007240 Tank Water Heater Booster 7.2 kW 240V

eEmax Auto Booster

Stiebel Eltron MegaBoost Tank Booster

Unlike the previous brands, Stiebel Eltron is an independent company based in Germany. While the Stiebel Eltron MegaBoost Tank Booster is competitively priced compared with Rheem and Eemax, it boasts superior heating abilities.

Unlike the others, the MegaBoost can be installed on the hot water outlet OR the cold water inlet. When the device is installed on the cold water inlet, it'll provide 71% more hot water. In addition, the recovery rate for the tank is also significantly reduced by up to 200%, and even better, it achieves its boosting effect at 100% efficiency. This makes the MegaBoost a top contender in the water heater booster market, and well worth buying.

However, the downside is that the MegaBoost draws more power and requires a separate hookup to your circuit breaker, which does make the installation more difficult and the energy-use higher.

Stiebel Eltron MegaBoost Tank Booster Water Heater

Stiebel Eltron MegaBoost Tank Booster

Final Thoughts

When you need more hot water, a water heater booster is an excellent alternative to upgrading your hot water heater. Any homeowner unsatisfied with their tank's capacity should consider adding a booster if they can afford the purchase and time required for installation

Compared to other hot water solutions, boosters are easy to install, cost a fraction of the price, and will likely satisfy your hot water needs. If you've unwillingly suffered from cold showers, consider upgrading your home hot water system with a water heater booster and enjoy nearly endless heat!

Remember, there's no shame in asking for help! Mistakes caused by inexperience can cause unexpected and significant expenses. If you're in doubt, ask someone to help you out!

This article was written by Jake Romano from John The Plumber, a plumbing service provider in Canada. John The Plumber is the plumber in Kingston that you can count on. We've been in the hot water game for a long time, and we'd love for the opportunity to help.

Related Posts