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

Margaret Wack
Written by Margaret Wack
Updated September 9, 2021
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The typical cost to install a hot water heater expansion tank 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.

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, it’s usually a good idea to hire a professional for this job. 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.

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.

Materials

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 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.

Labor

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

FAQs About Hot Water Heater Expansion Tanks

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Do you have to replace expansion tanks at the same time as your hot water heater?

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.

Are hot water heater expansion tanks necessary?

While many older homes don’t need hot water heater expansion tanks, they’re necessary in some newer homes. These tanks are required by code in areas where there are backflow preventers or pressure regulators on the incoming water pipe between the public water pipes and the water heater.

How do hot water heater expansion tanks work?

When the water expands in a hot water heater, it puts pressure on your hot water pipes and can cause leaks or a rupture in the hot water tank under certain conditions. Pipes or water heaters may split due to the pressure where there is a backflow preventer that prevents the hot water heater from diffusing pressure by releasing water back to the public water line.

In these scenarios, a hot water heater expansion tank provides a place for the hot water heater to relieve pressure and prevent bursts and leaks. Hot water heater expansion tanks are fairly small, with a typical capacity of about two to five gallons.

Are hot water heater expansion tanks required for warranty coverage?

Depending on the brand of water heater, you may need to install an expansion tank in order to meet the conditions for warranty coverage. It’s important for consumers to read the fine print of the warranty to see if an expansion tank is necessary.

How can I extend the life of my hot water heater?

Installing an expansion tank is one way to help extend the life of your hot water heater and prevent costly repairs. You should also drain and flush your hot water heater on a regular basis.

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