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How Long Does It Take To Install a Water Heater?

Learn how much it costs to replace a water heater and how long the installation process will take in your home.

Blue wall, White hot water heater

One of the worst experiences is getting ready to take a hot shower, only to turn the shower handle on and be splashed in the face with freezing cold water. While this experience could just be a sign of a circuit breaker tripping, if your water heater is also making strange noises and leaking or producing rusty water, it could be time to replace it.

So you may be wondering, how do you replace a water heater, and how long will it take to install?

On average, it takes a licensed plumber about two to three hours to replace and install a new water heater as long as there are no complications. Installing a water heater requires plumbing, electrical, and carpentry skills to ensure the process is done safely and correctly. 

Continue reading to learn when to replace different types of water heaters and how much they cost to install. You will also find out the benefits of tank and tankless water heaters and if it is safe to put in a new water heating unit on your own. 

Is Installing a Water Heater Hard?

Installing a water heater is not hard, provided you have the requisite skills and knowledge. Replacing and installing a water heater can be dangerous if you do not know what you are doing.

If you are installing an electric water heater, you need to have experience with electrical wiring, plumbing, and water hookups. A gas water heater is a bit more complex to install since you will also need to know how to work with soldering, gas lines, and vent lines. 

Water heaters cannot be installed anywhere in your home as you need to follow the building codes of the town or city where you reside. You must also install your water heater in an easy-to-reach place that does not flood and where you can frequently have it serviced. 

Water heaters should also never be installed in a closet or enclosed space as there will not be proper ventilation, and you and your family could be at risk for carbon monoxide poisoning. You also must make sure you have the correct permits, or you could face legal troubles. 

Can You Install a Water Heater Yourself?

Bottom of large hot water heater and pipes

It is not recommended that you install a water heater yourself as many safety and financial risks are involved. If you do not have the proper skills or training to install a water heater, you could put yourself and your family members in a dangerous situation. 

Suppose you install a water heater incorrectly or have a faulty temperature and pressure relief valve or even no valve at all. In those cases, you could cause water damage and a massive explosion. This disaster could lead to tens of thousands of dollars in damage and pose a significant safety risk to your family.

Improperly connecting a water heater to a gas line could also cause gas leaks leading to a fire. Homeowner’s insurance and water heater warranties also require a licensed plumber to install a water heater. If you install the heater yourself, your homeowner’s insurance will not cover any damage, and the warranty will be void. 

To install a new water heater, you also need special permits from your town or city, and the water heating installation must meet local building codes. Many places will also not grant a permit unless a licensed plumber does the installation. 

To prevent all these risks, avoid replacing a water heater yourself and hire a skilled and licensed plumber to do the job. 

How Long Does It Take for a Plumber To Install a Water Heater?

Hot water heater with dials, hand turning dials

Now that you know you should hire a plumber to replace your water heater, you may be wondering about the installation process. It should take a plumber approximately two to three hours to install a typical water heater. 

Plumbers will first need to remove the old water heater before putting in the new one. They will need to disconnect the water heater from the electricity and plumbing and drain the tank before removing it. 

Once the old tank is removed, the plumber will need to bring in the new tank and connect it to the power and water lines. After they secure the water heater to the proper sources, they will test it to ensure the system works and make any adjustments needed. Installing a gas water heater may take a bit longer since you also need to connect the water heater to the gas supply line.  

Tankless water heaters can take more time to install, particularly if you switch from a tank heater to a tankless heat system. In this case, you may need to hire a plumber and an electrician to update electrical wiring and add new vents for proper ventilation.

How Long Does It Take To Install a 40-Gallon Hot Water Heater?

The standard size water tank in most homes is 40 or 50 gallons. Larger homes and houses with hot tubs tend to require bigger water heating tanks, with the largest tank size usually being 120-gallons. So you may be wondering if your tank’s size will affect the installation time of your water heater. 

Typically a larger water heater does not require much more time for a plumber to install compared to a smaller water heater. It may take more time if you have more than one water heater installed at once and if you are switching from gas to electric or from a water heater with a tank to one without a tank. 

How Much Does It Cost To Have a Water Heater Installed?

Underneath a water heater showing water dripping and wires

Hot water heaters’ lifespans and installation costs vary based on the power source they use to operate and whether they have a tank or are tankless. 

Most tank water heaters typically last around eight to twelve years, while tankless water heaters can last up to 20 years. Electrical water heaters also last longer than gas water heaters as they do not need to be replaced until 10 to 15 years. 

Tank water heaters cost less to install than tankless water heaters and are the better option if you are on a budget or need to replace your unit in an emergency. Installing a new tank water heater will usually cost between $1,300 and $2,000. Gas tank water heaters tend to be more expensive than electric tank water heaters, but they typically cost less to operate. 

Tankless water heaters are usually much more expensive than standard tank water heaters and have higher installation fees. A tankless water system will cost you between $1,200 and $5,000 to install in your home, with the average price being $3,500. 

While tankless water heaters cost more up-front to install, they will save you more money over time by being more energy efficient and using less hot water, thereby cutting your monthly utility bills. 

Continue reading to learn when to replace different types of water heaters and how much they cost to install without the assistance of a home warranty plan.

Should I Replace My Water Heater Before It Fails?

Small white hot water heater

It is a good idea to remove and replace your water heater before it fails. Suppose you wait to replace your water heating unit until an emergency. In that case, it can lead to a stressful situation and be quite expensive, as you will be without hot water and will have to pay extra installation fees so that a plumber can fix the water heater quickly. 

Experts recommend you start to plan to replace your water heater once it turns ten years old or two years before the predicted end of its lifespan, depending on the unit. By planning ahead, you can start saving for the cost and installation of a water heater. You can also order a heater before your current one fails in case there are long wait times for the type of water heater you want in your home. 

Signs that you should start getting ready to replace your water heater include if the unit is making banging or rumbling noises and if there is a drop in water temperature. Water that has an odor or is rust-colored can also indicate that it is time to change your water heater.


Water heaters are relatively quick and easy to install, as long as you hire a professional plumber and replace them before they fail. While replacing water heaters can be a bit pricey, having a professional install it properly will give you peace of mind and ensure a working water heater for years to come.