Top 15 Best Horizontal Water Heater Reviews 2022

Are you tired of your traditional water heater taking up so much space in your home? If so, consider a horizontal water heater. This type of water heater is designed to take up less space, making it a great option for those who are tight on space. But is a horizontal water heater the right choice for you? Keep reading to find out.

Horizontal Water Heater Comparison 2022

Horizontal Water Heater Reviews 2022

Best For On-the-go – Atwood New RV 6 Gallon Gas/Electric GC6AA-10E Water Heater DSI

This RV water heater is small and lightweight for an easy fit in your cabinet. It uses automatic gas-driven pilots to heat up the liquid fast, as well as electric heating elements that recover 6 gallons per hour.

The Atwood New RV 6 Gallon Gas/Electric GC6AA-10E Water Heater DSI is great for RVs. It is small and lightweight, making it easy to fit in any RV cabinet, and it recovers up to 6 gallons of water per hour. 

This water heater is also battery-powered, so you don’t need to worry about plugging it into an outlet. The Atwood New RV 6 Gallon Gas/Electric GC6AA-10E Water Heater DSI is a great choice for any RV owner. 

Pros

• Small and lightweight, easy to fit in any RV cabinet.
• Recover up to 6 gallons of water per hour.
• Battery-powered; no need to worry about plugging it into an outlet.

Cons

Best For Standard House – Iheat Electric Tankless Water Heater Model AHS21-D

Having a water heater on hand in an emergency is always a good idea. Horizontal water heater models are especially beneficial because they take up less space, making them ideal for smaller homes or apartments. The Iheat Electric Tankless Water Heater Model AHS21-D is one such model.

This horizontal water heater is designed with a digital display that features both Celsius and Fahrenheit options, making it easy to use no matter where you live. Additionally, the heat exchangers are made from 100 percent stainless steel to avoid corrosion. 

This horizontal water heater is also easy to install, with fittings on the inlet and outlet that are easy to grip. Plus, it comes with new flow technology for even heating throughout the tank.

Finally, this horizontal water heater is equipped with an advanced power modulation microprocessor that helps conserve energy and save money on utility bills. 

Overall, the Iheat Electric Tankless Water Heater Model AHS21-D is a great choice for anyone looking for a horizontal water heater that is easy to use and efficient.

Pros

• Easy to install.
• Corrosion-resistant.
• Advanced power modulation microprocessor conserves energy.
• New flow technology ensures even heating throughout the tank.
• Digital display with Celsius and Fahrenheit options.

Cons

• It can be difficult to install in certain areas.
• It is not as aesthetically pleasing as some of the other options on the market.

Best For Villa – Rheem RTEX-24 24kW 240V Electric Tankless Water Heater

I was recently in the market for a new water heater and decided to use a horizontal water heater. After doing some research, I decided on the Rheem RTEX-24. This water heater has a few great features that I really love.

The first thing I love about this water heater is the off/on dial control with an adjustable digital temperature display. This makes it easy to set the desired temperature and know exactly what temperature you are at. 

The second thing that I love is the self-modulating power control. This means that the power output of the water heater will adjust automatically to meet the hot water demand. This is a great feature, especially since my family uses a lot of hot water at once. 

The last thing I love about this water heater is the external digital thermostatic control with an LED display. This control allows you to adjust the temperature with +/- 1-degree accuracy. This is great because it ensures you always have the right hot water temperature.

Overall, I am really happy with my horizontal water heater and recommend it to anyone looking for a new one! 

Pros 

• Off/on Dial Control with adjustable digital temperature display. 
• Self-modulating power control. 
• 24-kilowatt Model Flow Rate: up to 5.9 gallons per minute for RTEX-24. 
• Bottom 3/4-inch NPT water connections. 
• External digital thermostatic control with LED display (+/1 degree accuracy). 

Cons 

• Some people may find this horizontal water heater difficult to install 
• It may not be as energy efficient as other types of water heaters. 

Best For Apartment – Bosch Thermotechnology – WH27 Tronic 6000 C Electric Tankless Water Heater

Suppose you’re looking for an efficient electric tankless water heater that will last a long time. In that case, the Bosch Thermotechnology – WH27 Tronic 6000 C Electric Tankless Water Heater is a great option. 

This water heater can provide hot water on demand for 1 – 3 major applications at a time, making it a great choice for households or businesses. 

It’s also easy to install, with a polymer-encased element and built-in flow sensor that helps to ensure a consistent output temperature. Plus, with its 97 percent thermal efficiency and minimal standby loss, this water heater is sure to help you save on your energy bills. 

Pros 

• Efficient to use energy.
• Last a long time.
• Consistent temperature.
• Control heat output.
• Easy to install.

Cons

Best For Dormitory – Eemax EX190TC 3-Gallon Series Two Whole House Electric Tankless Water Heater

If you’re in the market for a whole-house horizontal electric tankless water heater, the Eemax EX190TC is a great option. It has a compact design that saves space and is 99 percent energy efficient, so you can save on your electric bill. 

The thermostatic control ensures precise outlet temperature and has a flow rate of 2 gallons per minute. The Eemax EX190TC is easy to install, with 3/4-inch NPT water connections on the bottom of the unit, and it doesn’t require a T&P valve. 

So if you’re looking for a horizontal electric tankless water heater that’s easy to install and can save you money on your energy bills, the Eemax EX190TC is a great choice.

Pros

• Save space.
• 99 percent energy efficient. 
• Thermostatic control provides precise outlet temperatures.
• The minimum flow rate is 0.7 gallons per minute, and the maximum flow rate is 2 gallons per minute.
• Easy installation.
• No T&P valve needed 
• On-demand hot water means you’ll never run out.
• 87 Fahrenheit temperature rise at 1.5 gallons per minute flow rate.

Cons 

Stiebel Eltron Tankless Heater – Tempra 36 Plus – Electric – ‎239225

The Stiebel Eltron Tempra 36 Plus electric horizontal water heater is a sleek and space-saving design that does not require venting, making it easy to install. The electronic switch is activated for virtually silent operation, and the copper-sheathed heating element is housed in a copper cylinder. 

It has a 7-year leakage warranty and a 3-year parts warranty. The max. The flow rate is 26 gallons per minute, making it perfect for multiple fixtures. It requires a phase-single 60-hertz voltage of 208-volt and a wattage of 27 kilowatts. 

This horizontal water heater is a great choice for those looking for an on-demand and continuous supply of hot water.

Pros

• The best part is that you can have it on-demand at any time.
• This sleek and modern design is perfect for small spaces
• Electronic switch activated for virtually silent operation.
• Heating up the house with a copper sheath.
• The warmth flows through my body as if it were liquid, gently soothing muscle aches and pains that sometimes only an ice pack can fix for good.
• Powerful heating element.
• 7-year leakage and 3-year parts complete warranty.

Cons 

Whale HF2000 Water Heater

The Whale HF2000 is a horizontal water heater perfect for homes, RVs, and boats. 

This water heater has a 20-gallon capacity and comes with a front heat exchanger with double-walled construction to prevent accidental contact with the freshwater supply. It also has an integrated pressure relief valve and temperature monitor. 

The horizontal-mount, 120-volt water heater is rated for 100 Pounds per Square Inch and is backed by a warranty of 2 years. The hold-down brackets are welded to the inner tank, and the shell is made from durable marine galvanized steel. 

This water heater measures 16 inches x 32 inches x 16 inches and weighs 48 pounds. If you are looking for a horizontal water heater that is reliable and space-saving, the Whale HF2000 is the perfect choice for you. 

Pros 

• Save space.
• Front heat exchanger with double-walled construction to prevent accidental contact with the freshwater supply.
• Integrated pressure relief valve and temperature monitor.
• Rated for 100 Pounds per Square Inch.
• A warranty of 2 years.
• Hold-down brackets are welded to the inner tank.
• The shell is made from durable marine galvanized steel.

Cons

Stiebel Eltron 232886 Tempra 36 Tankless Electric Water Heater

Horizontal water heaters are becoming more and more popular, and for a good reason. They’re sleek, compact, and take up very little space. The Stiebel Eltron Tempra 36 Tankless Electric Water Heater is one of the best horizontal water heaters on the market. It’s reliable, efficient, and has a simple design that makes it easy to install. Plus, there’s no need for venting, making it a great choice for homes with limited space.

One of the best things about the Stiebel Eltron Tempra 36 is that it can provide an endless hot water supply. Whether you’re taking a shower, doing laundry, or washing dishes, you’ll never have to worry about running out of hot water. And because it’s tankless, you’ll save money on your monthly energy bill.

If you’re looking for a horizontal water heater that’s both efficient and stylish, the Stiebel Eltron Tempra 36 is a perfect choice. It’s a great option for any home, and you’ll love the endless supply of hot water it provides.

Pros

• Sleek, compact design.
• No venting is required.
• Easy installation.
• Provide an endless supply of hot water.
• Saves money on energy bills each month.
• Advanced microprocessor technology ensures water temperature never deviates from the set point.

Cons

• Require a minimum 200-ampere electrical service. 
• 3 wire service with ground required. 

Whale Seaward 6 Gallon Hot Water Heater ‎S700

The Whale Seaward 6 Gallon Hot Water Heater ‎S700 is a great horizontal water heater choice for your marine vessel! This electric water heater is made with high-quality materials and features an automatic ignition system that makes it easy to get started. 

Additionally, the Whale Seaward 6 Gallon Hot Water Heater ‎S700 comes with a front heat exchanger that helps to keep your living space warm.

The Whale Seaward 6 Gallon Hot Water Heater ‎S700 is a high-quality horizontal water heater that is perfect for marine applications. It features a robust stainless steel construction that offers high levels of corrosion resistance, as well as safety controls and ignition protection. 

Besides, this water heater comes with multiple versions to suit your installation, making it a versatile option for any boat. Overall, the Whale Seaward 6 Gallon Hot Water Heater ‎S700 is a great choice for those in the market for a horizontal water heater.

Pros

• High-quality materials.
• Corrosion resistance. 
• Safety controls.
• Ignition protection.
• Multiple versions to suit your installation. 

Cons

• It can be slightly difficult to install.

Eemax HA036240 240V 36 kW Electric Tankless Water Heater

This horizontal electric tankless water heater from Eemax is a great choice for those looking for an efficient and reliable way to heat their water. 

With 99-percent thermal energy efficiency, this unit saves you money on your energy bills, and because it doesn’t require a large storage tank, it also saves you space. 

Additionally, the computer-controlled micro-processing temperature control ensures that you always have hot water at the precise outlet setting you need. At the same time, the scald prevention feature keeps you safe from dangerous temperature levels and spikes. 

This unit also lasts nearly twice as long as a traditional tank heater. 

Pros

• Save energy and money.
• No tank to store water, so it takes up less space.
• Computer-controlled micro-processing temperature control for precise outlet settings.
• Scald prevention feature.
• It last nearly twice as long as a traditional tank heater.

Cons

Whale Premium Water Heater ‎S360EW

The Whale Premium Water Heater S360EW is a great horizontal water heater for boats. It is quick and efficient in heating water and can maintain hot water for up to 10 hours. This makes it ideal for use with deck showers and warming wetsuits. 

It has an efficient 300-watt heating element that delivers outstanding performance. The water heater also includes an integrated temperature and pressure relief valve. It conveniently uses 12-volt D.C. power supply, so there’s no need for a generator, inverter, or shore power. 

Plus, it installs in compact spaces such as under seating, in the galley, or transom. The Whale Premium Water Heater S360EW is a great horizontal water heater option for boats of all sizes!

Pros

• Quick and efficient in heating water.
• It can maintain hot water for up to 10 hours.
• Efficient 300-watt heating element delivers outstanding performance.
• Integrated temperature and pressure relief valve.
• Conveniently use 12-volt D.C. power supply.
• Install in compact spaces such as under seating, the galley, or the transom.
• Durable epoxy-coated aluminum case.

Cons 

• It requires 12-volt D.C. power, so it may not work with some types of generators or shore power.
• It may not be suitable for larger boats.

Craftsman CMXTEPA0036 36kW 240-Volt 7.3 GPM Electric Tankless Water Heater

This horizontal water heater is a space-saving alternative to the traditional bulky tank water heater. It is perfect for warm to hot climates and can serve up to 3-4 bathrooms. 

The digital control panel allows you to easily set the desired temperature up/down in increments of 1 degree Fahrenheit from 90 – 122 degrees. 

This water heater is made with durable assembly with stainless steel, non-corrosive, lead-free internal canisters, and piping with standard 3/4 in. NPT (straight thread) fittings.

The construction of the horizontal water heater is very durable. I like that the horizontal water heater is very space-saving. I appreciate that setting the temperature with the digital control panel is easy. 

So far, it has worked great and provides continuous hot water flow whenever we need it. I highly recommend this product.

Pros 

• Space-saving alternative to traditional bulky tank water heaters.
• Easily sets the desired temperature with a digital control panel.
• Durable construction with stainless steel, non-corrosive, lead-free internal canisters, and piping. 
• Continuous hot water flow whenever needed. 

Cons 

Eemax HA027240 Tankless Electric Water Heater

The Eemax HA027240 Tankless Electric Water Heater is a highly durable and efficient water heating system. The digital temperature display and control knob makes it easy to adjust the temperature to your desired level. 

The recommended wire size of 3 x 8 inches  AWG ensures that you’ll have no problems with energy consumption or performance problems. 

Additionally, the copper heat exchanger with brass top help to keep your water at a consistent temperature, and the Scald prevention feature provides an added layer of safety. 

Overall, the Eemax HA027240 Tankless Electric Water Heater is an excellent choice for anyone needing a reliable and efficient water heater.

Pros

• Highly durable. 
• Efficient.
• Precise temperature control.
• Space saving.

Cons 

Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater

The Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater is a sleek and compact water heater that is perfect for smaller homes or apartments. 

The digital output temperature display makes it easy to see the current water temperature, and the tankless design means you never have to worry about running out of hot water. This water heater is also 99.8-percent energy efficient, meaning that you will save money on your monthly energy bill. 

The required breaker for this water heater is 4 x 40 A or 150 A, and it comes with a 3/4-inch NPT pipe fitting. Overall, the Ecosmart ECO 36 is an excellent choice for those looking for an energy-efficient and reliable water heater.

Pros  

• Sleek and compact design.
• Digital output temperature display
• 99.8-percent energy efficient.
• High flow rate.

Cons 

• The required breaker may not be compatible with older electrical systems. 

RecPro RV Tankless Water Heater ‎RP-1057

The RecPro RV Tankless Water Heater ‎RP-1057 is a great little machine. It is perfect for anyone who likes to camp or use their RV in the winter. 

I love that it has a frost protection setting. This is perfect for those cold mornings when you are trying to get the water heated up for a shower. The flame-out protection is also a great safety feature. 

If your flames happen to go out, the machine will turn off. This prevents any hazardous situations from happening. Overall, I am very pleased with this purchase.

Pros

• Small and compact.
• Easy installation.
• Flame out protection.
• Water and gas linkage control.
• Frost protection.
• The forced exhaust structure keeps air safe and clean when entering the combustion chamber.
• Dust net prevents dirt from getting into the tankless water heater.
• A low water pressure startup makes it easy to use.
• Exhaust with a forced fan eliminates harmful gasses.

Cons

• It may not provide enough hot water for a large RV or if multiple people are showering simultaneously.

Factors To Consider When Choosing Horizontal Water Heater

When it comes time to replace your home’s water heater, you may choose horizontal or vertical models. Horizontal water heaters have been gaining popularity in recent years because they take up less space and are easier to install. But which one is right for your home? Here are some factors to consider when choosing a horizontal water heater:

Sizes

When buying a horizontal water heater, it is important to know the different available sizes. There are mini horizontal water heaters, small horizontal water heaters, medium horizontal water heaters, and large horizontal water heaters. 

Which size horizontal water heater you need will depend on how much hot water you need at one time. The larger horizontal water heaters can hold more hot water and meet the demands of a larger household or commercial space. 

However, it is important to note that the larger horizontal water heaters may also take up more space and require a bigger installation area. It is important to carefully consider your space before purchasing a horizontal water heater. 

Installation Costs

Installing a horizontal water heater can be costly, but there are ways to reduce those costs. Here we will look at some factors that will affect the installation cost and how you can save money on your horizontal water heater purchase.

Firstly, the size and type of horizontal water heater you choose will affect the installation cost. Generally, larger horizontal water heaters require more work for installation and therefore cost more. Higher-end models may also require additional parts or specialized installation, resulting in higher costs. 

Additionally, the location of your horizontal water heater can affect installation costs. If the horizontal water heater is placed in a difficult-to-access location, such as an attic or crawl space, it may require extra installation time and labor. 

One way to save on installation costs is to purchase your horizontal water heater from a company that offers installation services, as they may have discounts or deals. 

You can also save by purchasing your horizontal water heater from a reputable retailer with competitive prices and buying any necessary installation materials rather than having the installer provide them. 

Overall, the cost of installing a horizontal water heater will vary based on factors such as size, type, location, and who you purchase it from.

Flow Rate

Flow rate is an important consideration when buying a horizontal water heater. The flow rate is the amount of water that can be heated in a minute and measured in gallons per minute (GPM). When choosing a horizontal water heater, make sure to select one with a GPM that meets your needs. 

For example, if you have low water pressure, you’ll need a horizontal water heater with a lower GPM than someone with high water pressure. It’s also important to consider the flow rate when determining the size and capacity of your horizontal water heater, as a higher GPM will require a larger tank. 

Be sure to research and select a horizontal water heater with the appropriate flow rate for your household’s needs.

Energy Efficiency

When it comes time to buy a horizontal water heater, energy efficiency is one of the most important factors you need to consider. A horizontal water heater that is not energy efficient will end up costing you more money in the long run, as you will be using more electricity to heat your water. 

Thankfully, many horizontal water heaters on the market today are highly energy efficient and will save you money in the long run. So how do you know which horizontal water heater is the most efficient? Here are some tips:

– Look for horizontal water heaters that have an energy star rating. These water heaters have been tested and certified by the government as energy efficient.

– Check the horizontal water heater’s Energy Factor (EF) rating. This measures the overall energy efficiency of the water heater, with a higher EF indicating a more efficient unit.

– Consider investing in a horizontal water heater with advanced technology, such as heat pump technology or condensing technology. These technologies can significantly increase the energy efficiency of the water heater.

Overall, taking the time to choose an energy-efficient horizontal water heater will save you money in the long run and also help to conserve energy. So do your research and choose the most efficient option for your needs.

Warranty 

When you buy a horizontal water heater, it is important to know what the warranty covers. Most horizontal water heaters come with a 1-year warranty, but some manufacturers offer longer warranties. 

Be sure to read the warranty carefully before purchasing a horizontal water heater to understand what is covered and what is not. It is also important to register your horizontal water heater with the manufacturer after purchasing it to ensure that the warranty remains valid. 

Overall, a lengthy and comprehensive warranty can give you peace of mind when investing in a horizontal water heater. It is worth taking the time to research different manufacturers and their warranties before deciding on which horizontal water heater to purchase.

Capacity     

When buying a horizontal water heater, it is important to consider its capacity. Horizontal water heaters range in size from 10 to 80 gallons. It is important to buy a horizontal water heater that is large enough to meet your needs. 

If the horizontal water heater is too small, it may be unable to keep up with hot water demands. On the other hand, buying a horizontal water heater that is too large can lead to wasted energy and higher utility bills. 

Consult with a professional to determine the proper size horizontal water heater for your household or business.

Housing’s Material Types

When it comes time to buy a horizontal water heater, there are many factors you will need to consider. One of the most important decisions you’ll have to make is what material the horizontal water heater will be made of. 

There are 3 main types of materials used in horizontal water heaters: copper, steel, and plastic. Each has its own set of pros and cons, which you will need to weigh before making your decision.

Copper horizontal water heaters are known for their durability and lifespan but may also come with a higher price tag. Steel horizontal water heaters have a lower initial cost, but they may not be as long-lasting as copper models. 

Plastic horizontal water heaters are often the least expensive option, but they may not be able to handle high water pressures as well as the other materials.

Safety Features 

If you are in the market for a horizontal water heater, it is important to know the safety features included. Some horizontal water heaters have a built-in thermostat that automatically shuts off the heater if it becomes too hot. This prevents overheating and potential fires. 

Other horizontal water heaters include a thermal cutoff switch, which will automatically shut off the heater if it runs out of water. This prevents the heater from being damaged by dry-firing. 

Be sure to ask your dealer about the safety features of each horizontal water heater you are considering.

Temperature Ranges

When buying a horizontal water heater, it is important to know the temperature ranges different models offer. Some horizontal water heaters are designed for colder climates, while others are better suited for warmer ones. 

By knowing what to look for, you can ensure that you find the perfect horizontal water heater for your needs. Regarding temperature ranges, there are 2 main factors to consider. 

The first is the minimum output temperature, which refers to how low the horizontal water heater can go before stopping heating the water. The second factor is the maximum output temperature, which refers to how high the horizontal water heater can heat the water before shutting off. 

Some horizontal water heaters offer a minimum output temperature of as low as 90 degrees Fahrenheit, while others can reach as low as 75 degrees. Similarly, some horizontal water heaters have a maximum output temperature of 140 degrees Fahrenheit, while others can reach 180 degrees. 

It is important to consider the temperature ranges offered by horizontal water heaters, as they can greatly impact the efficiency and effectiveness of the unit. 

Make sure to research and choose a horizontal water heater with temperature ranges that meet your needs.

Ultimately, the best water heater for your home will depend on various factors related to space and budget constraints. Consider all of these factors before deciding to ensure you choose the horizontal water heater that’s right for you.

FAQs About Horizontal Water Heater

What is a horizontal water heater?

A horizontal water heater is a water heating system that sits horizontally on the floor, as opposed to a vertical water heater which sits vertically on the wall. 

Horizontal water heaters typically have a larger storage capacity than vertical water heaters and are great for homes with limited space. They’re also easier to install and often more affordable than vertical water heaters.

How does a horizontal water heater work?

Horizontal water heaters run cold water into the top of the unit, where it is heated and then sent back to use. This is a more efficient way to heat water, as it eliminates the need to wait for hot water to travel from the bottom of the tank. 

Why would I want a horizontal water heater? 

Horizontal water heaters typically take up less space, making them a good option if you’re short on room. They’re also easier to install and can be more cost-effective to operate than vertical models. Additionally, horizontal water heaters often last longer than vertical models.

What are the benefits of horizontal water heaters? 

Horizontal water heaters offer several benefits when compared to traditional vertical water heaters. Perhaps the most noticeable benefit is that horizontal models take up less space, making them a good option for small homes or apartments. 

Additionally, horizontal water heaters are more efficient than vertical models and often have a longer lifespan. 

Finally, horizontal water heaters often cost less to operate than vertical models. Overall, horizontal water heaters offer a compact and cost-effective option for households needing a new water heater. 

However, horizontal water heaters may not be the best choice for every household. For example, horizontal models typically have lower gallon capacities than vertical models, so they may need help to meet the hot water needs of larger households. 

Besides, horizontal water heaters can be more difficult to install and require special venting systems. Before purchasing a horizontal water heater, it is important to carefully consider your household’s hot water needs and consult with a professional for advice on installation requirements.

Conclusion

The Rheem RTEX-24 is a horizontal electric tankless water heater that delivers up to 24kW of power, making it perfect for homes or small businesses with three or more bathrooms. This unit can provide hot water on demand for up to two showers and one sink simultaneously, making it an ideal choice for busy households. 

The RTEX-24 also features freeze protection and a digital display that lets you know the temperature of your incoming water and the output temperature of the heated water. Installation is simple, thanks to a versatile design that allows you to mount the unit horizontally or vertically. Overall, the RTEX-24 is a reliable and efficient horizontal water heater option.

Horizontal water heaters are an excellent choice for those who want to save energy and money. They are also great for homes with limited space because they take up less room than traditional water heaters. Don’t wait – order your horizontal water heater today!