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Tank vs Tankless Water Heaters

Are you trying to determine which type of water heater is right for your home? The decision can be a complicated one. Each system has unique advantages and disadvantages, so choosing the perfect water heater will depend on your situation.

Hot water is essential for any home. It’s something we rely on every day of our lives, whether we use it to take a shower, wash dishes, or clean our clothes. Without it, we’re inconvenienced on a daily basis—we’re stuck standing under an icy faucet after a long day of work, or dealing with stacks of dirty dishes! To avoid these dilemmas, you need to choose a water heater that can meet your needs.

We’re going to discuss everything you need to know about water heaters using our years of experience in the plumbing industry, from how they work to what they cost. To find out which water heater is best-suited for your home, keep reading: 

How Tank Water Heaters Work

These traditional systems are in the majority of older homes; they’ve been around for years, and there’s a reason for that. A tank water heater, which is powered by electricity or gas, constantly heats a storage tank of hot water to the desired temperature. Inside that insulated tank is a heating mechanism that keeps the water warm.

When you use hot water, it draws from the tank storage until it’s depleted. The tank will require time to heat more water. Once the heating element raises the water temperature to the desired level, the system is ready to deliver more.

How Tankless Water Heaters Work

Also known as “on-demand” water heaters, tankless systems are designed for energy efficiency. When you call for hot water, they respond by producing it that very instant. Unlike tank heaters, they don’t heat and store water ahead of time.

A tankless water heater accomplishes this via the heat exchanger. As the water passes through this device, the temperature rises rapidly. With this technology, tankless water heaters don’t require any type of storage tank to hold hot water.

This model aims to resolve the inefficiencies of traditional tank water heaters; they’re also significantly smaller due to the lack of storage tank (hence the name tankless).

Tankless Water Heater Pros and Cons

To help you assess whether a tankless water heater is right for your home, here’s a list of their main benefits and drawbacks:

Pro: Their energy efficiency will lower your utility bills. These systems are estimated to save between 24-34% more energy than tank water heaters. If you’re eco-conscious, this offers another bonus—tankless water heaters waste less energy, which is better for the environment. Even though these models are pricey to install, their low operating costs can make up for that in the long run.

Con: Tankless water heaters are more expensive up front, both to purchase and to install. This is especially true if you need to replace an existing tank water heater system—retrofitting can be costly.

Pro: They tend to last longer than tank water heaters. With proper maintenance, they can last twice as long as a tank system! Even though tankless water heaters have a higher initial cost, this will pay off in the long run—you’ll replace them less often than tank water heaters.

Con: One of the main drawbacks to a tankless water heater is its lack of storage, which can cause a low-flow rate. Running too many appliances at once will strain your system. Tankless water heaters can only supply so many appliances with hot water at one time. If you’re doing laundry and washing dishes, you might end up with cold water in the shower. 

Pro: They save space! The lack of a storage tank makes these systems a lot more compact. You won’t have to dedicate an entire room to store your water heater.

Tank Water Heater Pros and Cons

On the other hand, you could purchase a traditional tank water heater, which has advantages and disadvantages of its own:

Pro: Traditional tank water heaters are more affordable to purchase and install. The cost of a tankless water heater is significantly more than a tank model.

Con: They take up more space than tankless water heaters. This makes it tricky to install tank water heaters in small spaces.

Pro: Tank water heaters typically cost less to repair. They’ve been around long enough that the design is streamlined, so most technicians are familiar with repairing it.

Con: You’ll pay higher utility bills with this water heater. The heating element constantly uses power to maintain the temperature of the water, which will raise your energy bill.

Pro: Tank water heaters can provide multiple appliances with hot water. This is due to their storage tank, which can store anywhere between 20-60 gallons, depending on the model that you purchase.

Con: Once you run out of hot water, you’ll need to wait before you can use more. Tank water heaters will need time to heat another tank of water before you can access it again.

Installation and Maintenance

It’s every homeowner’s dream to purchase an appliance that never breaks, but sadly, that isn’t the case with water heaters. These systems are used in your home every day, which means they experience a lot of wear and tear. Here’s how the installation and maintenance of these systems differ from one another:  

Tank Water Heaters

Many homeowners opt for tank water heaters simply because of their lower installation costs. But before you can install this unit, you need to dedicate space for the storage tank.

If the unit requires repairs, it tends to be less expensive to repair traditional models. The tank water heater model has been around long enough that it’s easier to find parts and technicians who understand these machines.

Tankless Water Heaters

One thing that holds homeowners back from purchasing a tankless water heater is the cost of installation. Not only are these units more expensive to purchase, but they are also complicated to install, especially if you currently have a tank water heater.

These systems are a lot easier to find space for since they’re so much smaller than traditional water heaters. However, maintenance of these units is a bit trickier due to their complicated design. Diligent care will pay off, given that tankless systems can last around 20 years (whereas a tank water heater typically lasts ~12).

How Do They Compare?

When you weigh the pros and cons of tank vs tankless water heaters, it becomes clear that depending on your situation, one is more optimal than another.

Just like choosing the right car, house, or HVAC system, the ideal water heater is dependent on what you need from the system. 

So, which type of water heater is best for your home? That depends on a few factors:

  • How big is your home? If you’re short on space, a tankless water heater might be best.
  • How many people need hot water? You won’t run into problems if you’re only drawing from tankless water heaters with one appliance. However, if multiple members of your household need hot water at once, you might be better off with a tank water heater.
  • Can you afford the upfront costs of a tankless water heater? Even if you’re interested in the energy efficiency of a tankless water heater, you might be faced with one obstacle: the cost. Tank water heaters are more affordable to purchase and install.
  • Are you interested in lowering your utility bills? Over time, you’ll enjoy savings on your utility bills with a tankless water heater, which offsets the setup costs. Since these systems only heat water when it’s requested, they aren’t constantly using energy to keep unused water warm like a tank water heater does.
  • How cold is the climate that you live in? The colder it is outside, the harder the heat exchanger must work to warm it up. This may take additional time during the winter months. Since tankless water heaters only supply hot water when it’s demanded, they have to heat groundwater at its given temperature. 


After reading this article, we hope you’ve found some clarity about which water heater will serve you best. However, you might have even more questions now than you started with!

At the end of the day, you can always consult your trusted local plumber for advice. At Master Rooter, our experienced technicians will be happy to answer any questions you might have about your water heater installation in Denver. We offer commercial and residential plumbing in Denver. Contact us today!

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