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5 Different Types of Water Heaters

In the market for a new water heater? The benefits and potential drawbacks of each model are fully explained in our buying guide.

Plumber installing water heater

Table of Contents Show

Quicklist: Water Heaters

  1. Conventional Storage 
  2. Tankless 
  3. Heat Pump 
  4. Solar-Powered 
  5. Condensing 

If you’re in the market for a new water heater, you may not exactly know what you’re looking for.

Of course, a water heater isn’t something you go out and buy every day and some people may only need to purchase one or two in their entire lifetime.

So, there’s no shame in not knowing anything about heating systems until, of course, you need to know. Worse still there are many different types on the market, such as electric water heaters, solar water heaters, on-demand water heaters, conventional water heaters, storage tank water heaters, gas heaters, tankless systems for heating water and high-efficiency water heaters.

If you are looking to buy a new water heater for your home and wondering what your options are, then you have found the right place.

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A. Five Different Types of Water Heater

There are five main styles of water heater available and each one has its benefits and potential drawbacks. Here’s a little bit about each style of water heater to help you choose which one is best for you and your home.

1. Conventional Storage Tank Water Heater

This style of water heater is the most popular and probably the one you are most familiar with.

a. What is a conventional storage tank water heater?

This style of water heater features a tank that holds water to be heated. This means that the capacity of the tank determines how much hot water you have available at once. The tank is insulated so that when the water heats up, it remains warm until it is needed.

This tank features two valves, the temperature control valve, and the pressure control valve. The temperature control valve opens to release heat and moderate temperature when the water reaches over 120 degrees Fahrenheit.

The pressure release valve opens to lower the pressure when it reaches about 150 psi. This is the most common type of water heater among family homes, but you are limited to how much hot water you can hold.

If your tank is too small or you need an excessive amount of hot water one day, you may run out and have to wait for the next tank to be heated.

b. What maintenance is required?

Because the tank works to store water constantly, you will need to clean it out regularly to increase the lifespan of your water heater. You should clean your water heater tank up to twice a year to remove sediment and mineral scale and help reduce corrosion.

This is not necessary and your water heater will usually work without being cleaned, but it may not last as long. The typical lifespan of a conventional storage tank water heater is around twelve years.

c. What are the benefits of this style of water heater?

This conventional style of water heater is typically the most affordable style and it pretty easy to install, as well.

d. What are the cons to buying a conventional storage tank water heater?

This style of water heater only holds so much water at a time. This amount is based on its capacity, meaning that a 40-gallon tank will provide you with a continuous stream of 40 gallons of hot water before it runs out.

Once the hot water is gone, though, it may take a while — sometimes an hour or more — to refill and reheat another 40 gallons of water.

2. Tankless Water Heater (On-Demand Water Heater)

The “tankless” water heater features modern technology and can offer nearly endless hot water for your home.

a. What is a Tankless Water Heater?

A tankless water heater, as you can probably guess, has no tank. Instead, there are super-heated coils that fill with water and heat water in a flash as you need it, which is why it is alternatively known as an on-demand water heater. This is great for heating water quickly, even for large families who need a large amount of hot water at once.

This style of water heater comes in different sizes, and you do need to ensure that you have the right size for your household, as a smaller tankless water heater will not be able to keep up with your water usage otherwise and it will result in lukewarm or cold water.

These models work well in homes that use natural gas to power their water heater, but larger models require a larger gas line and more gas to run correctly. Larger tankless hot water heaters that run on electricity may require you to increase the electricity capacity of your home, which could be costly.

b. What kind of maintenance is involved?

Although there is no tank, you should still clean your tankless water heater at least once a year to remove mineral scale and avoid corrosion. Cleaning may be more difficult as the parts are smaller and more difficult to access. The lifespan of this style of water heater is 8–10 years.

c. What are the benefits when compared to other styles of water heaters?

Tankless water heaters are incredibly energy efficient because they only heat water on demand instead of holding heated water all day, even when it is not being used. Assuming you get a model large enough for your household, you will have unlimited hot water all the time.

d. What about the downsides?

The initial investment in purchasing a tankless hot water heater is significantly higher than that of the more traditional style, and it may require larger gas lines or more power capacity than your home currently has (not always), which can be an expensive renovation.

3. Heat Pump Water Heater (Hybrid Water Heater)

This water heater hybrid can help save money on electricity because it doesn’t directly generate heat.

a. What is a Heat Pump/Hybrid Water Heater?

This style of water heater is unique in that is uses heat in the air and in the ground to heat water. This means that electricity is only used to move heat from the ground or air to the water, instead of the alternative where electricity is used to generate heat.

Heat pump water heaters can use up to 60 percent less electricity than traditional styles of water heaters. Because the pump is on the top, you may need quite a bit of room for this water heater, sometimes up to eight feet of vertical clearance.

b. Is there maintenance involved?

This water heater has a tank and, like conventional storage tank water heaters, it needs to be cleaned regularly (up to twice per year) to prolong its lifespan.

c. What are the benefits of heat pump/hybrid water heaters?

This water heater is incredibly energy efficient and, therefore, can be incredibly cost-efficient in the long run.

d. What about cons to this style of water heater?

Because this water heater style relies on pulling heat from the ground or air around it, it will not work very well in cold spaces like basements or in climates where it is excessively cold for long periods throughout the year. It is, however, one of the most expensive styles of water heaters to purchase.

4. Solar-Powered Water Heater

A solar powered water heater allows you to draw energy from the sun. This is a great idea if you already have solar panels or are considering adding them.

a. What is a solar powered water heater?

This style of water heater may be the most energy-efficient of them all and relies on roof-mounted solar panels as its energy source. The energy is transferred to a closed loop system containing a heat-conductive material, which then heats the water in the tank.

This can save lots of money on sunny days and works particularly well for those who live in warm, sunny climates. However, this system often requires a backup plan, such as natural gas or electricity, so that the water heater can continue to run on cloudy days.

b. What kind of maintenance should I do?

Again, this system has a tank, which should be cleaned regularly to remove scale and prevent corrosion. You should also consider the necessity of maintenance on the solar panels.

c. What are the benefits?

These water heaters are super energy efficient and therefore are very environmentally friendly as well. You can save tons of money every month on electricity if you allow the sun to do most of the powering for your water heater.

d. What about the drawbacks?

These solar-powered water heaters are expensive and sometimes it can take up to 40 years to see a return on your investment. In not favorable weather conditions where there is little to no sun, you may need an alternate source of power for your water heater, which can be a hassle.

5. Condensing Water Heater

This water heater uses your home’s unused gas fumes to heat your water.

a. What is a condensing water heater?

The condensing water heater may be the absolute best option if your family’s home uses primarily natural gas as its energy source. This type of water heater funnels heated exhaust from the natural gas system and uses it to heat the water, which is held in a tank much like the conventional version of the water heater.

The gas fumes funnel through a coil placed at the bottom of the tank to heat the water. Therefore, very little energy is used (aside from gas already burned elsewhere, in your oven or heater, for example) to heat the water for your home.

It is a tank style water heater, so you will need to be sure to purchase one large enough for your family size.

b. What kind of maintenance will I do?

Just like other styles, there is a tank to clean. This style may also require its gas import valves to be cleaned once a year as well.

c. What are the benefits of this style of water heater?

This is usually the most energy efficient version for families who heat their home with natural gas. Generally, there is plenty of water to go around since this style of water heater usually requires a larger tank.

d. Are there any drawbacks to this style?

This style of water heater is not easily available in smaller models and works best for families that need a capacity of over 55 gallons. It also won’t be the best choice for homes that don’t run on natural gas.

B. Top Brands of Water Heaters

1. Conventional Storage Water Heaters

A conventional storage water heater.

A.O. Smith, which is recognized as the largest, most reliable manufacturing company of residential and commercial water heaters in North America, is a public company that was established in 1874. A.O Smith is located in Milwaukee, Wisconsin; however, its largest water heater factory is located in Tennessee.

Storage tank-style water heaters are the most common type.” 

These conventional water heaters from A.O. Smith meet all regulations set forth by the NAECA (the National Appliance Energy Conservation Act (1987)) and are available for purchase in various commercial and residential tank styles and sizes, depending on the owner’s needs.

A.O. Smith’s high-efficiency water heaters can be powered by gas or electricity, with each type offering independent benefits, including ease of installation and low cost of operation. In addition, specific models are certified Energy Star, which may make the purchase of a new conventional hot water heater eligible for a rebate.

2. Tankless Water Heaters

Portable Tankless Water Heater, GASLAND Outdoors 6L 1.58GPM Propane Water Heater for RV Camping, Overheating Protection

The Tankless EcoSmart is available in a number of sizes (and various kilowatts/power), depending on the need and intended use by the consumer. Tankless water heaters offered by EcoSmart are both economical and thermally efficient in terms of operating costs.

And if the correct size of tankless water heater is selected, this innovative device can offer a never-ending supply of hot water on demand. The tankless water heater from EcoSmart is also a space saver. Its size is often up to 90% smaller than the more traditional storage water tank heaters.

EcoSmart’s dependable water heaters apply self-modulating technology, which is capable of reducing the use of electricity when the water heater’s full power is not in use or needed.

Note, however, that the electricity required to safely and appropriately power may require additional circuit breakers when compared to more conventional water heaters.

3. Heat Pump or Hybrid Water Heaters

50 gal. Residential Electric Water Heater, 4500W

Heat pump water heaters work off the concept that it’s easier (and cheaper) to use existing heat than it is to create heat.”

A heat pump (a.k.a. hybrid) water heater moves heat rather than directly generating the heat in a specific location. This technology makes these types of water heaters quite energy efficient.

Heat-pump or hybrid water heaters have multiple uses as they are used in homes, commercially, and often for creating the perfect pool water temperature.

Rheem’s hybrid (heat pump) water heater collection is offered in various sizes depending on the required and intended water usage. Many of these modernized water heaters are Wi-Fi enabled, allowing the owner to control the hybrid water heater using any mobile device from any location.

In addition, Rheem’s hybrid water heaters have the potential to reduce energy usage by up to 75%. Rheem also offers a 10-year warranty, plus an in-home warranty during the first year of ownership.

4. Solar-Powered Water Heaters

A solar-powered water heater on house roof top.

Solar water heaters (which are often called solar domestic hot water systems) create hot water without taxing a home or commercial electric grid.

Alternate Energy Technologies solar water heater typically includes a solar collector and a storage tank. Solar water heaters are usually backed up with a natural gas or electricity power source in the event of cloudy or overcast days.

Solar water heaters are offered in two types — active systems (direct and indirect systems) or passive water heating systems (integral collector or thermosyphon systems). Heaters powered by the sun are available in various models, styles and prices.  

5. Condensing Water Heaters

Rinnai RU130eP Condensing Tankless Hot Water Heater, 7 GPM, Propane, Outdoor Installation

Rinnai ultra-efficient condensing heaters that are gas-powered can use either natural gas or propane. In addition, the Rinnai condensing water heater models are energy certified/qualified. They are available for indoor or outdoor use.

Condensing water heaters are gas-fired units that operate similarly to a traditional mode with endless water; only they do so without the heat waste conventional heaters give off. Essentially, the water vapor created from the burning gas is condensed to release its heat.

Condensing hot water heaters can be on the expensive side but offer significantly lower operating costs due to cutting-edge technology and innovation. This is why they tend to make smart long-term investments.

 

Energy consumption

C. When to Replace a Water Heater

There are a few things you should look for to help you determine if you need to replace your water heater. Of course, if it isn’t working, it’s a no-brainer. But you may think it’s working just fine and really you’ve long needed a replacement. If you’re wondering if you should upgrade, consider this:

1. Your Warranty is Out

One good way to know that it may be time for an upgrade is when you’ve surpassed your 12-year warranty by a few years. Not only do you no longer have coverage for fixing your water heater if any sudden damages occur, but chances are your water heater’s design is  outdated and is using more energy than necessary.

This could be costing you tons of excess money every month without you noticing. If your water heater has lived long past its life expectancy, it may be time to toss it out and replace it with an upgrade.

2. Your Water Heater is Leaking

Usually, when your water heater is leaking, you’ll need a plumber to fix the issue. This can be costly and time-consuming. Sometimes, water heater leaks can be hard to find, and a lot of water damage can occur before the issue is fixed.

If you have a leak, you can have a plumber look at it. If it’s bad enough, you’ll probably be better off buying a new water heater instead of paying to fix the leak.

3. You Run Out of Hot Water When You Need It

If you find that you are frequently taking lukewarm showers or running out of hot water while doing the dishes, you may not have a water heater big enough to surmount the hot water volume your family uses. This means you may need an upgrade to a water heater with a bigger tank.

4. Your Building Codes Changed

Another reason you may need a new water heater is if it no longer fits your community’s building codes. You should check your local building codes regularly and, if you’ve moved states, you may have different building codes than before. If your building codes have changed, your water heater may need to as well.

D. How to Choose a Water Heater

1. Warranty:

Water heater warranties can vary greatly both in cost and length. Because your water heater is such an integral part of your family’s day to day life, you should always pay close attention to the warranty terms when choosing a new water heater.

In the event that it is damaged, you may be able to get a new one without shelling out thousands of dollars on demand. Warranty ranges are typically around 2–10 years, but you can find manufacturers who offer up to a 12-year warranty.

If you own your home, you might consider a longer warranty, even if you must pay a bit extra, to avoid any surprise costs in the future. Because water heaters can break, and they are so important, we suggest you choose the longest warranty available.

2. Drain Valves: Plastic or Brass?

The drain valve is located near the bottom of your water heater and is used to drain the water heater before maintenance or to make it easier to lift while moving it. This valve is typically either made of brass or plastic.

In the event that you need to replace your water heater drain valve, or you are purchasing a new water heater, you will need to decide which type to use. Both plastic and brass are particularly cost-efficient options. Plastic may be less reactive, although neither material is corrosive.

Brass is much more durable than plastic, and also more malleable, so it will take more damage. Brass is not affected by temperature change like plastic may be. This is not a huge decision, but it is still one you will need to make.

3. Anti-Scale Devices:

Mineral scale can cause damage to your water heater and other water-consuming appliances. Certain manufacturers include anti-scale devices in their water heater. This device moves the water at the bottom of the tank.

The constantly moving water is less prone to mineral build-up, which can increase the lifespan of your water heater. This feature may work, but there are other factors besides mineral build up that can damage your water heater.

It is not necessary to purchase a water heater with an anti-scale device and, with a lengthy warranty, you probably don’t need one.

4. Glass-Lined Tanks:

You may notice that some water heaters include a glass lining inside them. This lining is actually porcelain enamel and the coating helps to protect the water heater (which is usually made from steel) from corrosion.

The enamel coating can do wonders in extending the life of your water heater but, due to the coating process, areas of steel are most often still left exposed.

The ceramic enamel coating is becoming more and more popular and may even be a standard design for some manufacturers today. Again, this is not a necessary inclusion, but it could definitely slow down the corrosion process inside your water heater tank.

5. Digital Displays:

Water heaters with digital displays are convenient because you can easily adjust your water heater settings to fit your personal needs.

You can easily adjust the output of your water heater, the water temperature, and some models even have a scheduling feature, which allows you to input the hours your house is occupied in order to increase the energy efficiency of the water heater by shutting off when you’re away.

Water heaters without the digital display will often only show basic readings, like overall temperature and water pressure. The digital display is definitely a modern water heater feature you want.

6. Capacity:

Determining the capacity of your water heater tank depends solely on the number of people using water in your house. It can be difficult to determine how large of a tank you will need since each person’s water usage may vary greatly.

You can use the first-hour rating (FHR) to help determine the water heater size your family needs. To calculate your family’s FHR, count the number of people in your home and multiply by twelve.

This means that a family of four has an FHR of 48 gallons. You can check the FHR of your water heater to determine if it will heat enough water for your home. Here is another good rule of thumb:

If your home only has one or two people, a 30-gallon tank should be sufficient.

  • If your home has two or three people, you may need a 40-gallon water heater tank.
  • If your home has three to four people, you should opt for something larger, around 40–50 gallons.
  • For more than five people, you should consider a tank that holds 55 gallons or more.
  • For eight people or more, you may need two water heaters to supply enough hot water to your home.

Of course, for tankless water heaters, you will need to use your FHR to determine what size to buy.

E. Where to Buy Your Water Heater

You don’t usually run into a huge “Water Heaters For Sale” sign every time you go to your local grocery market, and if you’ve never bought a water heater before, you may not know where to look. Luckily, you have a few options:

1. Your Local Hardware Store

Sometimes, local family-owned hardware stores will have a small selection of water heaters. If not, they may know exactly where to get the one you need and can probably order it for you. Of course, you will have to wait for shipping. They probably offer delivery for a small fee, too.

2. Home Improvement Stores

If you have a chain home improvement store near you, you can rest assured they have a pretty big selection of water heaters available. When buying a water heater from a home improvement store, you will have expert staff available to help you make your decision.

3. Check the Web

You can usually order from your local home improvement store online and have a water heater shipped to you. You can also check Amazon—especially if you need a smaller water heater.

F. Frequently Asked Questions

How long do water heaters last?

For a residential location, a tank hot water heater will last an average of eight to 12 years. A tank water heater is the traditional type of water heater. A tankless water heater can last up to 20 years. 

What temperature should a water heater be set at?

It is recommended that the water heater temperature is set to 120 degrees Fahrenheit. If the temperature is below 120 degrees, it becomes a potential risk for bacteria to grow inside your water heater. Although 120 degrees is the recommendation, the standard default is 140 degrees Fahrenheit. 

Are water heaters gas or electric?

Most water heaters are powered by either electricity or gas. Water heaters can run on oil, propane, or solar energy, but that is far less common. 

Do water heaters use electricity?

All water heaters use electricity, even those that use gas to heat the water. However, they still require electricity to power hardware. Therefore, your water heater will not work if there is a power outage. 

Does home insurance cover water heaters?

Technically, no, home insurance does not cover hot water replacement. However, it can be claimed on your homeowner’s insurance when the damage was caused by peril or was unpredictable. This is when the damage has not been caused by old hardware or appliances that were not adequately maintained. 

How long for new water heater to heat up?

A new water heater that was installed professionally heats up quickly. The average water heater is 40 gallons, and it takes about 30 to 40 minutes to heat up. A larger tank of 80 gallons takes about 60 to 70 minutes to heat.

Are water heater gas valves interchangeable?

Water heater gas valves cannot always be interchanged. There are some brands that have specific connections and valve styles to ensure that gas flowing to the pilot and burner equals the output. Also, heaters with different fuel sources use different types of valves. 

Can a hot water heater freeze?

Yes, it is possible for a water heater to freeze if water is left inside it. If the power goes out when the temperature is below freezing, it is possible that the water can freeze, expand and cause the tank to burst. 

Do water heaters have filters?

Yes, a water heater has a filter. The job of the filter is to protect the water heater from scale. The filters use a unique blend to prevent scale from forming. 

Are water heaters recyclable?

Yes, water heaters are made from steel, with brass and copper components. These metals can be broken down for scrap. 

What size water heaters are there?

You can find water heaters in many different tank sizes. The sizes include 40 gallon, 50 gallon, 66 gallon, 75 gallon, 80 gallon, and 120 gallon. The most common water heater size is 40 gallon.

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