DIY Water Heater Replacement: A Step-by-Step Guide

by Keira June 11, 2020

written by Keira June 11, 2020

How to Replace a Water Heater: A Step-by-Step Guide

Replacing a water heater can be a daunting task, but it’s one that many homeowners can tackle with the right tools and know-how. In this comprehensive guide, we’ll walk you through the steps of replacing a water heater, from disconnecting the old unit to installing the new one.

Safety First

Before you begin, it’s important to take safety precautions. Turn off the water supply to your home and shut off the gas or electricity to the water heater. If you’re replacing a gas water heater, make sure to turn off the gas supply at the main valve.

Tools and Materials You’ll Need

Tools:

Adjustable wrench
Channel-lock pliers
Tubing cutter (if needed)
Screwdrivers
Garden hose
Appliance dolly and straps
Propane torch and sweat-soldering supplies (if needed)

Materials:

New water heater
Shims (as needed)
Plumbing fittings (as needed)
Plumbers pipe-seal tape
Water heater draft hood (if needed for a gas heater)
Temperature- and pressure-relief valve (if not provided)
Water heater drain valve (if not provided)
Vent pipe fittings (as needed)
Galvanized plastic-lined water heater nipples (2)
Water heater flex tubes (if needed)
Flexible gas tube (if needed)

Step-by-Step Instructions

1. Disconnect the Old Water Heater

Turn off the water supply at the main water shutoff valve or at the isolation valve on the incoming cold water line.
For an electric water heater: Turn off the electricity running to the unit by switching off the corresponding circuit breaker.
For a gas water heater: Turn off the gas supply at the shutoff valve nearest the water heater.
Disconnect the hot and cold water lines using a pipe wrench or channel-lock pliers for compression or union fittings. Use a pipe cutter to disconnect water lines with soldered connections.
Next, the power source for the water heater needs to be disconnected.
- For an electric water heater: Remove the cover on the junction box at the top of the water heater. Unscrew the wire connectors and cable clamp to disconnect the water heater.
- For a gas water heater: Use a pipe wrench or channel-lock pliers to disconnect the gas line from the gas control valve on the water heater.
If you’re replacing a gas water heater, disconnect the draft hood from the vent pipe.

2. Remove the Old Water Heater

Use an appliance dolly to move the old water heater out of the way.
Clean the floor where the new water heater will be installed.

3. Install the New Water Heater

Move the new water heater into place, ensuring that the existing connections line up with the water heater’s connections.
Level the new water heater by shimming under the legs, as needed.
Install the temperature and pressure relief valve and discharge drainpipe, as well as any other fittings as needed, following the manufacturer’s directions.

4. Connect the Water Lines

Wrap the threads of two galvanized plastic-lined nipples with plumber’s tape, then thread the nipples into the cold water inlet and hot water outlet openings on the top of the water heater using channel-lock pliers or a pipe wrench.
Depending on the configuration of the plumbing, you may just need to reconnect the flexible tubes by screwing them onto the galvanized nipples. However, in most cases, you will need to prepare new pipe assemblies to reconnect the water lines.

5. Connect the Gas or Electrical Lines

For an electric water heater: Clamp the electrical cable into the wire connection box at the top of the water heater. Connect the circuit wires to the water heater leads, using wire connectors. Attach the cover plate on the wire connection box.
For a gas water heater: Connect the gas line to the gas burner control valve and check for leaks by turning on the gas supply valve and brushing a soapy water solution onto the gas union and all gas joints. If you see any bubbles, the connection is leaking and needs to be tightened.

6. Reconnect the Vent (Gas Heaters Only)

Position the draft hood at the top of the water heater over the exhaust opening, slide it into the vent pipe, and secure it with sheet metal screws.

7. Complete the Installation

Set the thermostat and turn on the cold water supply valve to refill the water heater. You will know the tank is full when water begins to flow from the hot water tap that was opened at the beginning of the job.
For an electric water heater: Restore power to the water heater circuit by turning the circuit breaker back on.
For a gas water heater: Make sure the main gas valve is opened and follow the manufacturer’s directions to confirm that the pilot light igniter is working properly.

Troubleshooting Tips

If you’re having trouble replacing your water heater, here are a few troubleshooting tips:

Make sure that the water supply is turned on and that the gas or electricity is turned off.
Check for leaks by turning on the water supply and checking for water dripping from any of the connections.
If you’re replacing a gas water heater, make sure that the gas line is properly connected and that there are no leaks.
If you’re having trouble getting the water heater to ignite, check the pilot light and make sure that it is lit.

When to Call a Professional

Replacing a water heater can be a challenging task, and it’s important to know when to call a professional. If you’re not comfortable working with plumbing or gas lines, or if you’re having trouble troubleshooting the problem, it’s best to call a qualified plumber or gas fitter.

Keira

Keira is a seasoned gardener with a rich background in education and a passion for transforming even the smallest, most challenging spaces into lush, productive gardens. With over two decades of experience in both teaching and gardening, she brings a unique blend of skills and insights to Life Science Art, where she shares her expertise through engaging and informative articles. Keira's journey into gardening began in her early years, inspired by her grandmother's ability to coax vibrant blooms and hearty vegetables from the rocky soil of their family farm. This early exposure to the wonders of gardening planted a seed of curiosity and love for plants that has only grown over the years. Before fully immersing herself in the world of gardening, Keira spent many years as a special education teacher. This role honed her patience, creativity, and problem-solving skills—qualities that have proven invaluable in her gardening endeavors. Her teaching experience also gave her a deep understanding of the diverse needs and capabilities of individuals, which she now applies to helping others learn to garden effectively, regardless of their starting point. Keira specializes in small-space gardening, low-income gardening, and cultivating plants in poor soil conditions. She understands that not everyone has access to vast, fertile lands or unlimited resources, and she is dedicated to making gardening accessible and rewarding for everyone. Living in urban areas or having limited outdoor space shouldn't be a barrier to enjoying the benefits of gardening. Keira has mastered the art of maximizing every inch of available space, whether it's a tiny balcony, a cramped backyard, or a window sill. Her innovative techniques and creative solutions help her readers grow a variety of plants in the most confined spaces. Keira is also a strong advocate for low-income gardening. She believes that everyone should have the opportunity to grow their own food and enjoy the therapeutic benefits of gardening, regardless of their financial situation. Through her articles, she shares practical tips on budget-friendly gardening methods, repurposing household items, and making the most of available resources. Her advice empowers individuals and families to start and maintain gardens without breaking the bank. Not everyone is blessed with rich, loamy soil. Keira's expertise extends to growing plants in less-than-ideal soil conditions. She provides guidance on improving soil quality, selecting hardy plant varieties, and employing sustainable practices to ensure a bountiful harvest, even in challenging environments. Her hands-on experience and proven techniques help gardeners turn even the poorest soil into a thriving garden. Keira's contributions to Life Science Art are invaluable. Her articles cover a wide range of topics, from step-by-step guides on planting and maintaining specific types of gardens to tips on dealing with common gardening challenges. She also delves into the science behind plant growth, soil health, and sustainable gardening practices, making complex concepts accessible to readers of all backgrounds. Beyond her technical expertise, Keira's writing is infused with warmth and encouragement. She understands that gardening is not just about growing plants; it's about fostering a connection with nature, finding peace and fulfillment, and building a community. Her personal anecdotes and down-to-earth advice resonate with readers, inspiring them to embark on their own gardening journeys with confidence and joy. Keira invites you to join her on Life Science Art, where she shares her wealth of knowledge and passion for gardening. Whether you're a seasoned gardener or just starting out, her articles offer valuable insights, practical tips, and the inspiration you need to create your own green oasis. Discover the joys of gardening with Keira as your guide and unlock the potential of your outdoor space, no matter how small or challenging it may be.