Nine Popular Types of Water Heaters

If you’re the type that loves to take a hot, long shower to relax and unwind after a tiring day, you should know about the types of water heaters that are available. It’s one of the most hardworking appliances in your house.

However, it’s not odd if you don’t know much about the various types of water heaters because you’ve most likely only bought one or two in your lifetime. But, what happens when your water heater breaks down after years of service and it’s time to pick out a new one? Where do you start?

This is when it’s necessary to know the different types of water heaters that are available to you. Knowing what they are, how they operate, and benefits and drawbacks of each one will help you pick one that’s energy and cost-efficient. We’ll dive into the nine most popular types of water heaters below.

1 Tankless Water Heater
There are many different types of water heaters available, and each one comes with benefits and drawbacks that can make them more appropriate for certain uses than others. Tankless Water Heater by Kevin Shorter / CC BY 2.0

9 Common Types of Water Heaters

If electric, storage-tank, solar, conventional, gas, or tankless types of water heaters seem confusing, let’s break each one down into categories and go through them one by one to give you a good idea on which one will work best for your needs.

1. Combined Space & Water Heating System

This type of water heater comes equipped with or without hydronic boilers. They’re an excellent choice if you’re looking for a replacement for your forced-air furnaces. They use optimized hydronic air handlers with bigger coils to transfer the heat, and this equals space heating. They’re a nice pick if you have a house that has lower heating needs because it provides space efficiency, more insulation, and lower air leaks. You only need a single unit, and this saves you space and energy usage.

With these heaters, they heat both your water and space. However, how efficient it is at heating one space doesn’t mean that it’ll be as efficient at heating the other. You have to purchase the right size for your needs. However, due to how novel it is, you might have a hard time finding someone who can install it correctly.

2. Condensing Water Heater

This type of water heater is very energy-efficient, and you may have heard of them referred to as condensing boilers. They run using gas, and they capture and use any extra fumes produced to heat the water. They pull the heat from the hot exhaust gas that the flue expels, store it, and then use the heat it extracted from the gas to pre-heat the water as it sits in the boiler.

As you may have guessed, this type of water heater has storage tanks just like you’d find on a conventional heater. The flue gasses get captured and blown through the coil in the heater’s base. This base allows the incoming water to get heated as it passes through.

This is a nice choice if you need to use roughly 55 gallons of hot water in a single use. If your household runs using natural gas with gas lines, this type of water heater will be very energy efficient when compared to other models. You’ll have enough hot water so you don’t have any fears of running out halfway through your shower. Apart from not being available in smaller sizes and being exclusively natural gas, these systems have everything you need.

3. Conventional Storage Tank Water Heater

Conventional types of water heaters were the first types on the wider market, and they’re still one of the most common options people have in their homes. In fact, you probably have this type of water heater in your home right now. This system comes outfitted with storage tanks of a specific amount where the water sits and gets heated to the appropriate temperature. So, the amount of hot water you have at any given time will depend on how large the heater’s tank is, so buying the correct size is essential.

These tanks have great insulation, and this helps ensure that the water stays warm after you heat it up and switch it off. Traditional setups come with dual valves, and one valve is for temperature control while the other is for pressure control. The former valve opens when you need to moderate the temperature or release heat after the water hits 120-degrees F. The second valve opens when the pressure climbs out to 150 PSI.

The biggest drawback of this type of water heater is that they can take a decent amount of time to heat up. If you’ve managed to use all of the hot water and need more, you’ll have to wait for the full tank to heat up again. With a 50 gallon size, this could take up to an hour before you get more hot water. So, only a certain amount of hot water is available at one time. However, this setup is very simple to use, install, and it’s cost-effective.

2 Conventional Water Heater
These are the most popular types of water heaters on the market, and you most likely have one in your home due to how widespread they are. New water heater by TheKarenD / CC BY-NC 2.0

4. Heat Pump Water Heater

Better known as an hybrid electric water heater, this option can save you a lot of money on your electric bill since the heating mode doesn’t use direct heat generation. So, you have lower power consumption. Instead, this type of water heater captures heat from the ground or air and transfers it to the water it heats. So, the electricity will only come on when the heat gets transferred from the source to the water tank.

This removes the need for the heater to depend on electricity 100% of the time. This means that your heat pump uses up to 60% less electricity when you compare it to traditional water heaters. However, you need to place the heat pump on top of the water heater, so you’ll need at least eight foot ceilings to accommodate this, and many basement ceilings aren’t that high. Also, since it needs an external heat source, this type of water heater may not be a smart choice if you live in a colder climate. Also, due to how expensive the upfront costs are, it could take a few years before you see any savings on your electricity bill to help offset it.

5. Hydronic Boilers

Hydronic types of water heaters are also called combi-boilers or segregated heating systems. They come with hydronic boilers, and the heat transfer happens in the heat exchanger. They are available without and with tanks. There is a flow control valve that ensures you get a consistent temperature, regardless of what the incoming water temperature is. So, you get a good amount of hot water at stable temperatures.

A bonus with this type of water heater is that they regularly last between 10 and 15 years with routine maintenance. The built-in parts and compact design means that you won’t have to buy the parts separately. The compact size is a nice space-saver as the water comes directly from the mains to reduce the need for a tank. You’re not likely to have to deal with water leakages when you get this heater.

It can help you save roughly 90% of your monthly bill. However, the installation process can be very expensive due to how intricate it is, and the heater itself is more complex. So, this means that any repairs you need will be more expensive. The time it takes to heat the water is also longer since there is no tank, so it’s not a good idea for big families.

6. Point of Use Water Heater

This type of water heater gets installed near supply fixtures and is smaller. They supply water out of the central heating unit, and you can get them without or with tanks. They also work wonderfully as backups when the primary heater needs electricity or gas to run, but not solar power.

You can save energy with this heater by allowing you to decrease the temperature setting on your central tank. You find them used a lot in guest bathrooms, hot tubs, and fixtures that utilize less than 20 gallons of water a day.

7. Smart Water Heater

A smart type of water heater can have tankless or thermostat-controlled systems that work side by side with your existing heater. They will even allow you to connect them to Wi-Fi, minimize water damage by detecting and alerting you to leaks, save energy by adjusting and monitoring the temperature, and kill bacteria inside the water heater itself by cycling the water temperature. However, you’ll have to have a professional install them and they are more expensive upfront.

8. Solar-Powered Water Heater

Solar-powered types of water heaters are very energy-efficient and eco-friendly. They depend on sunlight for their energy, so if you’re someone who needs an alternative way to heat your water and you have or plan to install solar panels on your home, it’s one to consider. The cells on the solar panel will capture the heat that transfers it through a heat-conductive material using a closed-loop system. This will eventually get to the tank and heat your water.

Due to the need to have sunlight to power it, this type of water heater is only appropriate for people who live in sunny areas. This hot water heater can save you a large amount on your electricity bills. However, even sunny areas don’t offer sunlight every day of the year. So, you’ll need a backup energy source for when the sun doesn’t shine, like electricity or natural gas. However, the reduced carbon footprint the rest of the year is well worth it.

They can convert up to 80% of sunlight into energy, offer unlimited hot water on sunny days, are cost-efficient, and they’re environmentally-friendly. Additionally, some places will give you tax incentives, utility rebates, or financial credits if you use this type of water heater.

However, this water heater can be very expensive in some parts of the world, and they won’t do well when it starts to rain. It can also be a hassle to maintain the different parts of this setup.

3 Solar Water Heater
Solar water heaters are very nice to have in sunny locations, but they have much higher costs when you first get them that tend to ward a lot of people away. Solar Water Heater by Owen and Aki / CC BY-NC-ND 2.0

9. Tankless Water Heater

As the name suggests, this type of water heater doesn’t have a tank where you would heat the water. Instead, it comes with coils that get extremely hot when you fill them with water, and this gives you instantaneous results. Tankless water heaters are extremely efficient, and they’ll heat a huge amount of water quickly. You get an endless supply of hot water on demand, and you’ll never have to worry about taking a cold shower, no matter how large your family is.

You can choose from different sizes when you order this type of water heater, and you should select the size that fits your needs if you have a bigger family. Picking a size smaller than required will result in cold or lukewarm water since you’re putting more demand on your system than it can take. They can run on electricity or gas, and the smaller models usually run on gas while the larger ones require electricity. The energy needs will fluctuate based on the power source and size.

Reasons to May Need to Replace Your Water Heater

If you think that you may need to replace your water heater, there are a few things you should consider. If it’s not working, this is an obvious sign. However, it could stop running as efficiently so you let it limp along until it dies. Below are the following reasons why you may need to replace your type of water heater.

Building Codes Changed

Maybe your community recently revamped their building codes to keep everyone safer and your water heater no longer meets them. You want to regularly check on your local building codes, and if you’ve moved to a different state, you could have different building codes than your previous state. If your building codes upgraded, you may have to switch your type of water heater too.

Water Heater Leaks

Typically, if the water heater leaks, you’ll need a plumber to fix it. This can be really time consuming and expensive. It can be difficult to pin down where your water heater is leaking from, and you can end up with a lot of water damage before you find it and fix it. If you find a leak, call a plumber. If it’s bad enough, you’re usually better off purchasing a new type of water heater instead of trying to fix the current one.

Run Out of Hot Water Routinely

If you find out that you frequently run out of hot water during your showers or that they’re always lukewarm, your water heater may not be big enough to support your needs and generate the hot water that your family requires. This means that the next type of water heater you buy will need a bigger capacity.

Warranty Expired

One good clue that it’s time to upgrade your type of water heater is that you have surpassed the original warranty by a few years. Now you won’t have coverage for fixing the water heater if it gets damaged, but your water heater will most likely have an outdated design and is drawing more energy than is necessarily needed. This could cost you a decent amount of excess money. If the water heater has survived long past the warranty, it could be time to replace it with a better model.

Water Heater Buying Recommendations

4 Buying Recommendations
Water heater – Insulation? By Chris Bohn / CC BY-SA 2.0 When it’s time to buy a new type of water heater, there are a few pieces you can keep in mind when you start to shop to help you compare different models. 

Anti-Scale Devices

Mineral buildup and scale can cause damage to the water heater or any other appliances that consume water, like the dishwasher. Some manufacturers include anti-scale devices inside of the water heater. This device will move the water from the bottom of your tank to keep it constantly cycling. This movement makes the water less prone to mineral buildup, and this can increase how long your water heater lasts.


Determining how large the tank on your type of water heater should be to meet your needs depends on how many people live in your home. It can be a challenge to figure out the tank size you will need since everyone’s water usage will vary and fluctuate. You can find the first-hour rating (FHR) to figure out what water heater size you need for the tank. To calculate this number, you want to count how many people are in your home and multiply this number by 12. So, a family of four will need a 48 gallon tank at a minimum. You can check the rating on your water heater to figure out if it’s large enough. Another good rule to follow is:

  • One or Two People – If there are only one or two people in the home, a 30-gallon tank should be large enough.
  • Two or Three People – If there are two or three people in the household, increase your tank size to 40 gallons.
  • Three or Four People – Slightly larger households will need a larger capacity at 40 to 50 gallons at a minimum.
  • Five or More People – You should consider getting a type of water heater that offers a 55 gallon tank or larger.
  • Eight or More People – You may need up to two water heaters to get a large enough capacity to support your hot water needs.

Digital Displays

Having a digital display on your water heater is convenient because it makes it easy to adjust the settings to fit your personal preferences. You can also easily adjust the water heater’s output, the water temperature, and some offer the ability to schedule the hot water. This allows you to put in the hours people are in the house to increase how energy-efficient the water heater is and switch them off when you’re out. Types of water heaters without a digital display will show very basic readings, like the water pressure and the temperature. This is a more modern feature to consider.

Drain Valves: Plastic or Brass

The drain valve is by the bottom of your water heater, and you use this valve to drain the water heater to make it easier to lift if you need to move it or before you perform maintenance. The valve can be brass or plastic. If you need to replace your water heater drain valve, or if you’re going to buy a new type of water heater, you’ll want to decide which one is best for your needs. Both brass and plastic are cost-effective, but plastic is less reactive. Neither material is corrosive. Brass is a lot more durable and malleable, so it can survive more damage. Brass also won’t get affected by the temperature as much as plastic.

Glass-Lined Tanks

Some types of water heaters have a glass lining on the inside of the tank. The lining is a porcelain enamel,and this coating will help to protect the steel the water heater is made out of from corrosion. The enamel coating can be a huge help to extend how long your water heater lasts, but, due to this coating process, you will find small steel areas still exposed. This coating is getting more and more popular with newer types of water heaters. This isn’t 100% necessary to have, but it can slow down how quickly your tank corrodes to make it last longer.


Warranties on your water heaters can vary greatly in length and cost. Because you rely on your water heater so much, you always want to pay very close attention to the warranty terms when you pick out a new one. If the water heater gets damaged, you should be able to get a new one without paying thousands of dollars. Warranties can range from 2 to 10 years, but you can find 12-year warranties with some companies. If you own your home, you’ll want to get a longer warranty, even if you pay more for it, to avoid surprise costs going forward. Since any type of water heater can break and they’re so vital, you want to pick out the best warranty possible.

Bottom Line

We’ve outlined nine popular types of water heaters to consider if you’re going to upgrade or install a new one. You can decide which ones work best for your needs, and you can use the short guide to ensure that you get the best water heater to ensure that you have enough hot water, whenever you need it.

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