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Is an Expansion Tank Required for a Water Heater?

Many people including the ones with a tankless water heater do not know if water heater expansion tanks are important. However, fixing this item to any water heater on a propane tankless heater or an electric tankless water heater isn’t necessary at all.

Before finding the perfect answer to your question “do I need an expansion tank on my water heater?”, you will have to know everything about an expansion tank. You will also need to know the conditions that determine if you need to purchase one. In this article, we will tell you all you need to know.

Expansion Tanks – What are they?

These are tiny sized water tanks that can contain two gallons of water. They hang beside the water heaters and fixed to the waterline of your building. They handle changes in water pressure that can damage your heater and plumbing in the long run.

When Do I Need Water Expansion Tank on My Water Heater?

Before fixing this item to your water heater, you should meet the following conditions.

  • If your water heater system does not allow hot water to mix with the public water supply system
  • If you use a check or pressure regulating valve
  • If you observe any changes in water pressure
  • If you are required (by law) to use an expansion tank
  • If you want to keep your water heater in good shape

What is the type of Water Heater Used in Your Building?

Using an expansion tank depends on the type of water heater in your home or business. For instance, if you use a regular storage heater, you will need to purchase an expansion tank.

But For those that keep asking do I need an expansion tank for my tankless water heater? The answer is NO because these models don’t need it.

How Does an Expansion Tank Work?

To know how an expansion tank works, you will need to know what happens in a water heater. If your heater converts cold water to hot, the liquid expands, thereby adding pressure to your pipes.

Imagine this process as pulling a rubber band. If you apply too much pressure, the band will break. Your heater is the rubber band, as it expands and contracts frequently, this will make leak or burst.

Most times, these problems occur in closed water systems that work with single valves. But if your water supply system allows heated water to move into the municipal supply, then your plumbing will not have these problems.

If many buildings in your city use closed systems, then the public authorities might require the city residents to use expansion tanks. Companies that even build water heaters recommend fixing expansion tanks, especially if you use their products with a closed system.

But do you know the type of water supply system in your building? If not, I suggest that you seek the services of a plumber as the setup might be confusing.

So what is the job of an expansion tank? Well, the tank prevents your plumbing from leaks and bursts and leaks. It performs this task by carrying the extra water while handling any changes in water pressure.

You can even see it as a backup to protect your closed water system. The reason is that the excess water does not strain the plumbing because it flows into the tank. Overall, the pressure is reduced to suitable standards.

What Size Of Expansion Tank Will Fit My Water Heater?

What Size Of Expansion Tank Will Fit My Water Heater 1

Now that you have an answer to the question, “do I need an expansion tank on my electric hot water heater?” You will have to check the size that will fit your closed water supply system. To do this, you will need to consider two factors.

  • The volume of water (in gallons) your water heater can hold. You can find this information printed on the label of your water heater.
  • The amount of water pressure. Sometimes, it might not exceed 30 psi. However, you can get this measurement accurately by using a portable gauge or calling your water supply provider

If you want to purchase an expansion tank, most companies offer a calculator or chart that will show the ideal size and model for your water supply system.

Since there are no general steps, you might have to perform some research on some site like the chart. You can also get some advice from your local plumber.

You must get an expansion tank in the right size for many reasons. For instance, if you use an undersized unit, the resulting pressure from the heated water can cause problems for your plumbing.

But if you choose an oversized expansion tank, there will be no issues. Indeed, it is advised to go for larger tanks, especially if you are not sure of the size to choose. Such tanks sizes can handle any need for your closed water system.

Wrap Up

An expansion tank is a small tank that is placed near a water heater. It reduces the pressure on the wall of the heater tank, thereby making the unit to last longer. They are usually cheap and easy to install.

If you use a tankless water heater, there is no need to fix this device. But if you own a regular heater, it’s vital that you attach an expansion tank.

If you have any questions or comments, you can place them in the comment box below.

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