Tank vs. Tankless Water Heater

Over the past decade, there has been a considerable increase in the use of tankless hot water heaters in the Conejo Valley. But why?

Tank and tankless water heaters can both be reliable options for your home. However, it is crucial to figure out which would suit you and your requirements best. In this comparison of tank vs. tankless water heaters, the experts at Conejo Valley HA Plumbing & Rooter discuss the basics of each water heater, so you have a better understanding of the differences between each.

If you are considering switching to tankless water heaters, but haven’t quite decided, here’s a quick guide to help you.

Tank vs. Tankless Water Heater: Which One is the Best?

What is a Tank Water Heater?

Storage tank water heaters generally have a capacity of 30 to 60 gallons. The capacity you want depends on your household size and how much hot water you require. Storage tank water heaters use natural gas, electricity, fuel oil, or propane to continuously heat water and keep a full tank ready at all times.

» How do Tank Water Heaters Work?

Traditional tank water heaters have been around since the early 20th century. The concept is simple: A reserve tank fills up with water and heats it. The heated water is distributed to your faucets until it’s empty. Once empty, the tank has to fill up with water and heat it again.

» Pros and Cons of Tank Water Heater

Since there are no perfect products, here are the good points and downsides to tank water heaters.


  • Lower upfront cost - A traditional tank-style water heater installed will usually cost less with tankless water heaters costing much more.
  • Simpler maintenance – While both types of water heaters require maintenance, a tank system usually costs less and is much simpler.


  • Runs out of hot water - Traditional water heaters are limited by their tank’s capacity and can run out of hot water.
  • Less energy efficient - Because tank water heaters are always on to keep the water in the tank warm, they use more power than tankless water heaters.
  • Large - Tank water heaters require a lot of space and won’t fit in tight spaces.
  • Don’t last as long - Traditional water heaters only last 10-15 years, whereas tankless versions can last up to 25 years.

What is a Tankless Water Heater?

As their name implies, tankless, instantaneous, or on-demand water heaters don’t have a tank for storing water.

A tankless hot water system heats water only when you need it. So if you’re the only one taking a shower, you don’t need to heat water for five. The same applies to washing dishes, clothes, and whatever else you need hot water for. You might need a gallon, 30, or maybe 100; there is no limit to how much hot water a tankless system can produce. Sounds great, right? But there are also some drawbacks.

» How do Tankless Water Heaters Work?

Tankless water heaters don’t have a storage tank for hot water. Instead, they only heat water when you need it. This is how tankless water heaters produce hot water instantly:

When you open a hot water faucet in your home, cold water travels into the heater and runs through a burner or heat exchanger, where heating occurs. Once hot, it directly flows to the tap or shower you turned on. These heaters can heat up to five gallons of water in a minute.

» Pros and Cons of Tankless Water Heater

Here are the various benefits to tankless water heaters, as well as their downsides:


  • Never runs out of hot water - Since tankless water heaters heat water on demand, you’ll never run out.
  • More energy efficient – Since tankless water heaters have no tanks, they don’t waste energy keeping the tank warm all day.
  • Takes up less space - You can fit tankless water heaters in tighter spaces since they have no storage tank.
  • Lasts longer - Tankless water heaters can last up to 25 years if well maintained.


  • High upfront cost – The biggest downside of tankless water heaters is the unit’s high upfront cost and installation.
  • Limited flow rate - A tankless water heater may be more efficient, but its output is also more limited to its flow rate.

What are the Differences Between a Tank Water Heater vs. Tankless Water Heater?

There are several ways in which these heaters differ that we can look into below, based on which you can then make a choice.

» Costs

Tank water heaters are generally more affordable than tankless water heaters in terms of purchase and installation costs.

Beyond the initial purchase and installation costs, tankless water heaters tend to be more cost-effective long term because they use less power than tank heaters to heat water.

» Energy Efficiency

Tankless water heaters are more energy-efficient in comparison to tank water heaters. They achieve this efficiency because they only heat water on demand instead of maintaining a constant supply and storage of hot water.

» Installation

When it comes to installation costs, installing a point-of-use tankless water heater will cost the least, followed by storage tank water heaters, then whole-house tankless heaters.

Some homeowners can DIY install traditional tank water heaters to save on water heater installation costs. However, it’s best to leave tankless water heater installation to a professional, as they are more complex.

» Size

Since traditional water heaters come with a storage tank, you need to account for that when setting aside some space for installation. On the other hand, tankless water heaters don’t have a tank, which is perfect if you don’t have plenty of room in your house.

» Performance

Tank water heaters hold a certain amount of hot water in their tank. If you choose the right size for your storage tank water heater, your home should not run out of hot water. On the other hand, since tankless water heaters heat water instantly, they might struggle to keep up with demand if two or more taps require hot water simultaneously. Thus, if your household demands a greater demand for hot water, you might need to install more than one tankless heater or install point-of-use models.

» Maintenance and Durability

Traditional tank water heaters have a lifespan of approximately 10-15 years, whereas tankless systems can last for over 25 years. Also, tanked water heaters require frequent maintenance to prevent rusting and other tank failures that cause leakages and damage your house.

Choosing the Right Water Heater for Your Home

» Parting Thoughts - Tankless Water Heater Vs. Tank Water Heater. Which Should I Choose?

We have now seen several ways in which tank and tankless water heaters are different from each other. So, which should you choose? Ultimately, it depends on your requirements.

Overall, it might be better to opt for a tankless water heater since it has the potential to save you a lot of energy and money in the long run. However, you might need to install several of these heaters if you have a higher demand for water at home.

When You Need A New Water Heater, You Can Rely on Conejo Valley HA Plumbing & Rooter

Still not sure which water heater is right for you? We can help! Contact Conejo Valley HA Plumbing & Rooter today, and we’ll talk through your needs and requirements so you can make the best decision for your homestead.

To learn more about our water heater services, Call (805) 499-0448 or contact us online today!

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