How Much Does It Cost to Install and Replace an Expansion Tank? [2023 Data]

Mizuki Hisaka
Written by Mizuki Hisaka
Updated May 10, 2023
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The typical water heater expansion tank cost is $90 to $350

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You may not think much about how your home heats hot water on a day-to-day basis, but reliable, on-demand hot water is essential, whether you’re taking a shower, doing the dishes, or washing your hands. Hot water heater expansion tanks can help protect your hot water heater and prevent it from exploding, ensuring you have hot water whenever you need it. How water heater expansion tanks cost an average of $220 to install.

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Hot Water Heater Expansion Tank Cost Breakdown

The main factors that influence the cost of installing a hot water heater expansion tank are materials and labor.


Most homes will need the 2-gallon expansion tank, which costs $40 to $60.

4-gallon expansion tanks are $60 to $90, while 4.4- and 4.8-gallon expansion tanks range between $60 to $140. For tanks over 5 gallons, you can expect to pay $140 to $200.

Water Heater Size (gal)Water Pressure (psi)Expansion Tank Size (gal)
40 – 6040 – 502
40 – 6060 – 803.2
8050 – 603.2


The standard type is the thermal expansion tank. These tanks will run between $40 to $200 depending on the size that you need.

There are also solar water heater expansion tanks that fit solar heating systems. You can expect to pay $110 for a 1.3-gallon tank, while 3.2-gallon tanks are $130.


The cost of an expansion tank ranges from $40 to $200. Most newer expansion tanks are bladder or diaphragm-type tanks, with a rubber bladder that expands and keeps the water separate from the main tank. Older tanks are often plain steel with no bladder. Smaller, two-gallon tanks tend to be less expensive than larger, four-gallon tanks.


You’ll also need to pay to get the water heater expansion tank professionally installed. This job typically costs between $50 and $150.

Cost to Install an Expansion Tank

The total cost to install an expansion tank is $90 to $350. This includes the cost of the tank and labor.

If you’re getting a brand-new water heater, the installation costs usually include the expansion tank. A new or water heater replacement costs $850 to $1,700.

Cost to Replace an Expansion Tank

The replacement cost for an expansion tank is $90 to $350, which includes labor.

The tanks usually last 5 to 10 years, so it’s a good idea to invest in a new one if you know the tank is nearing the end of its lifespan. Additionally, some signs of a tank going bad to keep in mind include dripping water or low water pressure inside the tank.

Additional Water Heater Expansion Tank Costs

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Consider some of these potential additional costs before you call a plumber.


Getting a permit helps ensure you don’t have water heater code violations. You should check with your local offices for exact costs, but water heater replacements usually require a permit that costs $100 to $1,500. You may be required to pay a similar or lower fee for an expansion tank replacement.


If you’re unsure if you need a new water heater expansion tank and want a pro to come take a look, you can expect to pay a plumber $45 to $200 per hour.

How Much Does It Cost to Install a Hot Water Heater Expansion Tank Yourself?

If you’re an experienced pro with extensive plumbing knowledge, you could save on the cost of labor and install a hot water heater expansion tank for $40 to $200. That said, hiring a professional for this job is usually a good idea. An improperly installed expansion tank can cause leaks, pipe bursts, and other issues. Get in touch with a water heater technician to discuss your options.

Ways to Save Money on Water Heater Expansion Tank Costs

While attempting a DIY job to save money may be tempting, it’s better to hire a plumber to get it done instead. Installation requires thorough knowledge of water heaters, and making a mistake could be costly and dangerous.

On the other hand, you may save money on a tank by buying the unit yourself instead of having your plumber buy one for you. Sometimes, you may be able to find a good deal online. However, make sure you’re buying from a reputable store and check if warranties are included before making a purchase.

Also, it’s worth noting that it’s typically not a great idea to install a water heater yourself. Get a professional to help make sure it gets done right and safely. Plus, they can help you figure out important details like the pros and cons of tankless water heaters.

Frequently Asked Questions

You don’t have to replace expansion tanks at the same time as your hot water heater. You may be able to go six to 12 years or more before needing to replace your expansion tank. At $90 to $350, hot water heater expansion tanks are usually much more affordable than the cost of hot water tanks themselves, which average about $1,190.

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