How to Install a Gas Water Heater: A Comprehensive Guide.

To install a gas water heater, first turn off the gas and water supply, disconnect the old unit, and connect the new one, following manufacturer instructions. Whether you’re replacing a broken water heater or upgrading to a newer and more energy-efficient model, installing a new gas water heater is not a difficult task if you have the right tools and knowledge.

A gas water heater is a popular choice for most households as it provides a continuous supply of hot water and is cost-efficient in the long run. In this guide, we will explain step-by-step instructions on how to install a gas water heater safely and quickly.

By following these steps, you can save substantial money by doing the installation yourself instead of hiring a professional plumber.

How to Install a Gas Water Heater: A Comprehensive Guide.


Pre-Installation Considerations

Choosing The Right Size Of Water Heater For Your Home

Getting the right size of water heater for your home depends on multiple factors. Larger families will need more hot water, and bigger water heaters may be required to supply it. Similarly, colder climates require larger heating units and vice versa.

Other essential factors to consider are the number of bathrooms in your home, the number of people in your household, and the water usage pattern. Here are some tips to ensure that you get the right size of the water heater:

  • Identify your household’s hot water demand.
  • Determine the flow rate of the fixtures and appliances that will use hot water.
  • Calculate the water heater’s first-hour rating (fhr) and its recovery rate.
  • Choose a water heater that can meet your demand while still being energy-efficient.

Sizing Up The Space For Installation

Installing a gas water heater requires ample space and adequate ventilation to avoid hazards such as carbon monoxide poisoning and fires. Before buying a water heater, you need to measure the space where it will be installed. It should fit the unit comfortably, allowing at least 6 inches of clearance around the tank’s sides and 12 inches above it.

Additionally, consider the following points:

  • The heater should be placed in an area that allows easy access to it for maintenance and repair.
  • Proper ventilation is necessary to avoid risks such as carbon monoxide poisoning or fire hazards.
  • The area also needs to have appropriate drainage, as water heaters are prone to leaks.

Obtaining Necessary Permits And Approvals

Before installing a gas water heater, you must ensure that all necessary permits and approvals are in place. Local authorities require permits to ensure that installation meets specific safety and regulatory standards. It requires a licensed plumber to perform gas line and electrical work.

The following are essential steps to follow:

  • Take the time to research local codes, permits, and requirements.
  • Check with your local building department to obtain any necessary permits.
  • Hire a licensed plumber to perform gas plumbing work.

Ensuring Proper Safety Measures Are Taken

Installing a gas water heater requires safety precautions to be taken to prevent accidents. Proper safety measures need to be in place to avoid risks such as gas leaks, fires, explosions, and carbon monoxide poisoning. Here are some essential safety tips:

  • Ensure that the gas supply is shut off before beginning installation.
  • Proper ventilation is required to avoid risks such as carbon monoxide poisoning and fire hazards.
  • Hire a licensed plumber to carry out the installation.

Gathering Tools And Materials

Tools Needed For The Installation Process

Before starting the installation process, it is important to ensure that you have all the necessary tools on hand. Here are the tools you need for installing a gas water heater:

  • Adjustable wrench
  • Pipe wrench
  • Flare nut wrench
  • Screwdriver set
  • Pipe cutter
  • Propane torch
  • Tin snips
  • Hacksaw
  • Level
  • Tape measure

Materials Required For Installation

Apart from the tools, you also need a few materials for the gas water heater installation process. Here are the essential materials:

  • Gas water heater
  • Flue hat
  • Teflon tape
  • Vent pipe
  • Flexible gas supply line
  • Mounting brackets
  • Pressure relief valve
  • Copper pipes
  • Drain pan
  • Pipe insulation
  • Pipe hangers

Importance Of Using High-Quality Parts

It’s crucial to use high-quality parts during the installation process to ensure the safety and longevity of your gas water heater. Cheap and low-quality parts may save you money initially, but they can cause you trouble in the long run.

Using high-quality parts ensures that your gas water heater runs safely and efficiently. It reduces the risk of potential leaks, fires, and other hazards. Moreover, high-quality parts can last longer, saving you money in the long run.

Make sure you invest in the best parts for your gas water heater installation process. As a result, you can enjoy hot water safely and efficiently for years to come.

Shutting Off The Power And Water

If you’re planning to install a gas water heater, shutting off the power and water to the existing water heater is the first critical step. This guide will explain the process of turning off the power, draining the old water heater, and disconnecting the gas line.

Follow these steps carefully to ensure a smooth installation process.

Turning Off The Power To The Existing Water Heater

  • Locate the circuit breaker that controls the power supply to your water heater.
  • Turn off the circuit breaker to shut off the power supply to the water heater.
  • For added safety measures, turn off the gas supply as well.

Draining The Old Water Heater

  • Turn off the cold water supply valve to the water heater.
  • Connect a hose to the drain valve and extend it to a safe location for draining the water.
  • Open the drain valve and let the water drain completely.
  • Once the tank is empty, open the relief valve to allow air to enter the tank and aid in draining any remaining water.

Disconnecting The Gas Line

  • Turn off the gas supply valve to the water heater.
  • Disconnect the gas line from the water heater using two wrenches, one to hold the gas valve still and the other to turn the fitting counterclockwise.
  • Once the gas line is disconnected, plug the line with a cap or a pipe plug to ensure no gas leaks occur.

Remember to check your local codes and regulations to ensure that you follow all necessary safety guidelines. Shutting off the power and water is just the beginning of installing your gas water heater, but it’s an essential step to prepare for the installation process.

Stay safe and follow these steps carefully to ensure a successful installation.

Removing The Old Water Heater

Gas water heaters play a vital role in many homes, helping households heat water for various purposes. If you are planning to install a gas water heater, you need to have some basic knowledge about the process. In this guide, we will look at the systematic process that will help you install a gas water heater effortlessly.

The first step in the process is removing the old water heater from its spot. Here’s how you can do it:

Unhooking The Plumbing Connections

Before you begin the removal process, you need to ensure that the gas supply and the electrical power are off. Once you have ensured the safety measures, you can move to unhook the plumbing connections. Here’s how:

  • Cut off the water supply to the heater.
  • Open a hot water tap in your home to relieve the pressure from the heater.
  • Turn off the gas supply valve next to the heater.
  • Unhook the cold and hot water connections from the heater, making sure there’s no water in the pipes.

Detaching The Old Water Heater From Its Stand

Once you have unhooked the plumbing connections, it’s time to detach the water heater from its stand. Here are the steps:

  • Remove the vent pipe from the heater.
  • Look for any auxiliary vent pipes that may need to be removed as well.
  • Detach the gas supply line.
  • If the heater is on a stand, remove the screws that hold the stand to the floor.

Now comes the next crucial step in the process, removing the old water heater. Follow these steps:

  • Use a hand truck to move the heater to its new location.
  • Position the hand truck so that the weight of the heater is evenly distributed.
  • Move the old water heater out of your home.
  • Make sure the heater is disconnected from all utility connections.

Removing an old water heater can be quite challenging. However, if you follow these steps, the process can be effortless and safe. Now that you know how to remove your old water heater, it’s time to move to the next step in the installation process.

Installing The New Water Heater

Installing The Stands For The New Water Heater

Before installing the stands, ensure that the floor is clean, dry and level. By following these four main steps, you can install the stands for your new water heater with ease:

  • Position the stand on the ground where you desire to place your water heater.
  • Make sure that the stand is level and adjust its position, if necessary.
  • Drill anchor holes in the stand’s base.
  • Use concrete anchors to attach the stand to the ground firmly.

Attaching The New Water Heater To The Stands

Attach the new water heater onto the stand in four easy steps:

  • Move the water heater to the stand, and ensure it’s level.
  • Align the mounting holes on the water heater with the holes in the stand and attach the water heater with the appropriate screws.
  • Ensure that the water heater is tightly fastened to the stand.
  • Double-check the stability of the water heater on the stand and adjust it accordingly.

Connecting The Gas Line

Connecting the gas line might seem daunting but by following these few steps, the process becomes relatively easy:

  • With the gas line close to the new water heater, fit the right connector end to the gas line.
  • Ensure the connector goes straight into the supply valve opening to avoid cross-threading.
  • Tighten the connector on the supply valve by turning it clockwise with a pipe wrench.
  • Repeat the process on the other end of the gas line by connecting the end to the gas regulator on the water heater.

Attaching The Plumbing Connections

When attaching the plumbing connections, ensure that the connections are tight to avoid leaks. Follow these simple steps:

  • Install the cold-water supply line to the water heater’s cold inlet, and using a pipe wrench, tighten it appropriately to avoid leaks.
  • Connect the hot water discharge pipe from the relief valve on the water heater and extend it to the sink or drain to let excess steam flow out.
  • Attach the hot-water outlet from the water heater’s top outlet to the hot water lines using the appropriate pipe fittings and tighten them firmly.
  • Double-check all your connections and joints for any leaks.

By following the above-listed steps, you can install a gas water heater with ease. Happy installing!

Testing And Fine-Tuning The Installation

Congratulations! You have successfully installed your new gas water heater. The final step is to test and fine-tune the installation to ensure everything is working correctly. Follow these steps to complete the process:

Filling The New Water Heater With Water

Before you can test your new water heater, you first need to fill it with water. Follow these steps to do so safely:

  • Close the cold water supply valve
  • Open the hot water faucet in your bathtub to release any pressure inside the tank
  • Connect a hose to the drain valve at the bottom of the water heater and run it to a suitable drain or outside
  • Open the drain valve and allow the tank to drain completely
  • Once the tank is empty, close the drain valve
  • Open the cold water supply valve and allow the tank to fill with water
  • Turn on the hot water faucet in your bathtub to allow the air to escape from the tank
  • Once the water is flowing steadily without air bubbles, close the hot water faucet.

Checking For Leaks

Before turning on your new water heater, it’s essential to check for any leaks. Follow these steps to do so:

  • Inspect all the connections, valves, and pipes for leaks.
  • Use a solution of soapy water and apply it to the connections.
  • Turn on the gas and let the water heater heat up for a few minutes. Watch the pipes and connections while it heats up.
  • If you see any bubbles forming, there is a leak. Tighten the connections and valves again and retest.

Adjusting The Temperature

The next step is to adjust the temperature of your new water heater. Follow these steps to adjust it:

  • Look for the temperature dial on your water heater. It is usually marked as low, medium, or high.
  • Turn the dial to the desired temperature. The recommended temperature is 120 degrees fahrenheit.
  • If you have a gas water heater, wait 20-30 minutes for the water heater to reach the desired temperature.

Testing The Pressure Relief Valve

The final step is to test the pressure relief valve. Follow these steps to do so:

  • Locate the pressure relief valve on your water heater. It is usually on the side of the tank.
  • Place a bucket under the pipe connected to the valve.
  • Lift the valve’s lever for a few seconds to release some water.
  • If the water flows out steadily and stops when you release the lever, the valve is working correctly.
  • If the water does not flow out or continues to flow after releasing the lever, you need to replace the valve.

Testing and fine-tuning the installation of your new gas water heater is just as important as correctly installing it. By following these steps carefully, you can ensure that your new water heater is safe, functional, and efficient.

Frequently Asked Questions Of How To Install A Gas Water Heater

How Long Does It Take To Install A Gas Water Heater?

On average, it takes 2-3 hours to install a gas water heater. The installation process involves turning off the gas and water supply, removing the old water heater, and positioning the new one. The installation time may vary based on the complexity of the job.

Can I Install A Gas Water Heater Myself Or Do I Need A Professional?

It is recommended to hire a professional plumber to install a gas water heater. Gas-powered water heaters are complex appliances and require experience and knowledge to install safely. A licensed professional plumber will ensure your safety and properly install the unit.

What Are The Benefits Of Installing A Gas Water Heater?

Gas water heaters are more energy-efficient and cost less to operate than electric water heaters. They heat water faster and supply hot water longer. They also tend to last longer than electric water heaters.

What Should I Consider When Selecting A Gas Water Heater?

When selecting a gas water heater, consider the size and capacity of the unit, the energy rating, your household’s hot water usage, and your budget. It’s important to select a unit that fits your family’s needs and has a high energy rating to save on energy costs.

How Often Should A Gas Water Heater Be Serviced?

Gas water heaters should be serviced annually by a licensed professional plumber. Regular maintenance and inspection will ensure that the unit runs efficiently, remains safe, and will prolong its lifespan. Regular maintenance can also prevent costly repairs.


Now that you have successfully installed your gas water heater, it’s important to remember to perform routine maintenance to ensure it continues to function properly. Regularly checking the pressure relief valve, flushing the tank to remove sediment buildup, and inspecting the anode rod can all extend the life of your water heater.

Remember to always follow the manufacturer’s instructions and safety precautions when performing maintenance or making repairs. Installing a gas water heater may seem daunting, but with the proper tools and guidance, it can be a successful diy project. Not only will you save money on installation costs, but you’ll also enjoy the benefits of a reliable source of hot water for years to come.

So, take the time to carefully install your gas water heater and enjoy the convenience and comfort it provides.