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What Size Tankless Water Heater Is Best For You (By Square Feet)

electric water heater on the grey tile wall

Choosing a new water heater can often feel like a thankless task for homeowners. After all, getting a new water heater installed can be expensive, and the time between now and your installation is often uncomfortable as you make do without hot water.

Not to mention that since the last time you purchased a water heater, there have been a lot of technological advancements and new water heater models introduced to the market. Our personal favorite? A tankless water heater.

However, just like with standard tank water heater systems, it can be difficult to decide what size tankless water heater is right for your home. That’s where we come in. As industry professionals, we will help you to weigh your options and find the water heater that is right for your home! Keep reading to learn more!

If you’ve never heard of tankless water heaters before, we are ready to blow your mind. These modern water heaters are:

  • Energy efficient
  • Eco-friendly
  • Perfect for small spaces

Keep reading to learn more!

tankless water heater outdoors

What Is a Tankless Water Heater?

Most of us are used to using a standard tank water heater. These older models work by having a tank filled with water that is warmed by a heating element at the bottom of the tank. When you turn on the tap, the hot water then flows through your pipes at the desired temperature.

Of course, there are some obvious problems with this design. If you live in a house with many other people and appliances, all using hot water, the water heater tank will inevitably empty. This means you will have to wait for it to refill and re-heat, which can be tricky when you are dealing with time constraints.

Enter: tankless water heaters. These new water heaters aim to address the problem homeowners face when using a tank water heater. Instead of storing water in a tank and heating it and replenishing it, tankless water heaters heat up the water only when needed.

The small, tankless unit is attached to your wall and has a heating unit inside it. As the water passes through the tank, it is immediately heated. This means that, in theory, you have access to a near-endless supply of hot water when you need it.

A tankless water heater is also a great choice for families looking to save money on their energy bills. Because tankless water heaters only heat water when you need it, as opposed to keeping the water at a steady temperature all day, they are a much more energy-efficient option.

What Size Tankless Water Heater Should You Have?

When choosing the right tankless water heater size for your home, there are three important factors to consider. Check out our list of the top determining factors here!

1) Size of Your Home

It might seem obvious, but knowing the size of your home can help you to understand which size water heater is right for you. We aren’t just talking about square footage, either! The number of people living in your home, the number of bathrooms, and the number of appliances (such as dishwashers and washing machines) that use hot water can all help you to determine which water heater will be right for you.

tankless water heater in the garage

However, you can also use square footage to help you make a rough estimate about which size is right for you. Knowing that the average US home is around 2000 square feet and the average tankless water heater size (we’ll get to that in a bit), can help you determine if that fits in your lifestyle or if a bigger option may be better.

2) Groundwater Temperature

The location of your home makes a big difference when it comes to the efficiency of your water heater. After all, living in a warmer climate, such as Texas, means that the groundwater temperature that your plumbing system is pulling from will be significantly warmer than the groundwater in, say, Wisconsin. This means it will take less energy to heat it, and you can use higher volumes of water at once.

3) Water Usage

Lastly, we recommend looking at your home’s overall water usage. While data shows that most homes use the majority of their hot water supply between 9-11 PM, that may not be the case for you.

If your family uses a lot of hot water all at once, you may need to invest in a larger water heater. However, if your usage is spread out throughout the day, you may be able to get away with a small one.

GMP: What Does It Mean?

Knowing the gallons per minute (GPM) that your tankless hot water heater can produce can help you to have a more accurate estimate of what size tankless water heater will work best for you.

It starts by knowing the GPM of the different appliances in your home.

  • Shower – 2-3 GPM
  • Dishwasher – 1.5-2 GPM
  • Washing Machine – 2-2.5 GPM
  • Sink – 1-2 GPM

Knowing these numbers, you can start to calculate how much hot water your family uses on an average day. You can then add this up in order to help you get an accurate estimate of how many GPM of hot water you need your tankless unit to produce.

turning the dial on a tankless water heater

Choosing the Right Tankless Water Heater

So, which one is right for you?

In general, most families are able to get by with a tankless water heater that produces 7-10 GPM. Of course, that unit of measurement usually only applies to gas tankless water heaters. If you are looking for an electric tankless water heater, the average homeowner typically buys one that uses between 15-28 kW of energy.

Get a Plumber’s Opinion

The best way to feel confident in your water heater purchase is to get a professional’s opinion! At Black Tie Plumbing, we have the experience to help you choose a tankless heater that meets your home’s specific needs. Once you’ve selected the size that is right for you, we will then install your new water heater in a timely manner, so you can get back to living your life. Contact us today to learn more about our services!

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