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Expansion Tank vs Pressure Tank: Which One Should You Choose?

Although they might sound the same, they actually have different purposes. But both of them are beneficial for your water supply, that’s for sure. For that reason, you’ve to know the differences before making a choice. 

What are the dissimilarities between an expansion tank vs pressure tank? 

The most significant difference between expansion and pressure tanks is their functionality. An expansion tank handles water expansion and provides protection for water valves and heaters. On the other side, the pressure tank lengthens the lifespan of the pump. Although both tanks have similar entry-level prices, they can vary from model to model. 

Anyhow, that was a short comparison of the two tanks. Keep reading if you want to know more information about them. 

So, let’s not wait around any longer and head right into it!

Expansion Tank vs Pressure Tank: Basic Differences 

Before we start a detailed discussion, let’s give you a small heads up. It gives you a surface idea that will help you with the comparison. 

For example, putting a water softener before or after a pressure tank requires prior knowledge. That’s why we’ve taken some time and provided a small chart for you- 

AspectsExpansion Tank Pressure Tank 
FunctionalityProtects the valves, heaters and prevent leaks in supply linesLengthen the lifespan of the water pump
Price Point 40$ to 200$50$ to 600$ or 1500$+
Durability5 to 10 years 4 to 7 years 
Installation Cost300$ to 400$ 250$ to 500$ 

After taking a quick look, which one do you prefer more? 

Expansion Tank vs Pressure Tank: Detailed Comparison 

If you still haven’t made a decision, don’t worry. We’ve discussed each of these aspects and which one should get a priority- 


Understanding the tank’s functionality is super important. Otherwise, it’s easier to make a wrong purchase which isn’t going to solve anything. 

Both of these tanks regulate pressure and prevent damages. But if your well pump is slowly building pressure, that’s a different story.

Let’s start with expansion tanks. As the name suggests, an expansion tank helps with water expansion. These tanks are usually connected with water heaters. 

Have you ever boiled water in a kettle before? When the heat is applied, water expands as steam. That’s why it lets off steam time after time. 

Except, the water system doesn’t have a way to let off the extra expansion. This damages the valves and heaters over time. It can cause leaks in the water system. 

That’s where the expansion tank comes in. It has a bladder in the middle which helps with maintaining the pressure. Because of this, the extra water will go inside during high pressure. 

Then the compressed air will push the water back when the pressure gets normal. This way your valves, heater, and supply line stay protected. 

In reverse, pressure tanks are related to the water pump instead. When low pressure occurs, your water pump starts immediately. But if it starts frequently, it can get damaged. 

The pressure tank also uses the same compression physics to store water. When the pressure gets low, this tank supplies the stored water instead.

This prevents the water pump from starting more often. Rather, it works less and provides a better water distribution. This way your water pump stays safe. 

The pressure tank can sometimes get waterlogged. But fixing a waterlogged galvanized pressure tank is easier than fixing water pumps.

Winner: If you have a water heater installed, go for an expansion tank. Otherwise, choose a pressure tank. 


Since water tanks are heavily used, more durability is always preferred. That’s why this segment should always be factored in. 

The average lifespan of an expansion tank is between 5 years to 10 years. They are super sturdy and can keep your system pristine for a long time. 

Likewise, a pressure tank also lasts a long time. Most pressure tanks will easily last 5 to 7 years without causing a problem. 

Therefore, whichever you choose, it’s going to be beneficial for you. 

Winner: The expansion tank lasts longer so it takes the crown in this round. 

Price Point 

The price point always affects overall decision-making. Water tanks are also no exception to this. Both of these tanks have a similar entry price. But the good ones cost a lot. 

The price varies depending on water capacity and pressure levels. 

The average price of an expansion tank is usually between 40$ to 200$. These are for residential purposes only. 

Nonetheless, expansion tanks ranging between 100$ to 150$ provide everything that you’ll need. 

On the contrary, the pressure tank can cost a lot. The price usually varies between 50$ to 600$. But the commercial pressure tank can cost up to 1500 US Dollars. 

Most of the apartments use bigger pressure tanks to supply the demand. Otherwise, a normal pressure tank should suffice. 

Speaking of expansion tanks, we’ve provided some of our top picks-

Product 1
Product 2 

You can easily grab whichever you like and get it installed! 

After buying the tank, you have to install it.  The installation cost of the two tanks varies due to sizes and complexities. 

But installing a residential expansion tank is generally easier than pressure tanks. Because pressure tanks always require a professional with a lot of knowledge. 

Winner: The expansion tank costs way less than pressure tanks.

After seeing the differences, hopefully, now you know which tank you should get! 


Question: What PSI should my expansion tank be?
Answer: An expansion tank should have an average water pressure of 50 to 60 PSI.  Maintaining this pressure is important. Because otherwise, it’ll fail and cause leaks in the water system. 

Question: Do expansion tanks need to be drained?
Answer: Yes. The expansion tank requires a draining session every once in one or two years. This will help the air pressure stay optimal which in turn, will provide peak performance. 

Question: Do I need an expansion tank if I have a pressure tank?
Answer: An expansion tank is always recommended if you have a water heater installed. Otherwise, pressure tanks can keep the pressure optimal. If there’s a check valve installed, it can benefit from expansion tanks. 

Final Words

That was everything we could put together and provide on expansion tank vs pressure tank. Hopefully, you’ve found your answer and are now able to make a decision. 

Finally, best of luck with your tank purchase!