How to Install a Gas Water Heater: A Step-by-Step DIY Guide

They'll be happy to install your gas water heater and dispose of your old heater as well. But if you're up for the challenge, you can save yourself some money by doing it yourself, follow the instructions below for some guidance. 

• Turn the gas supply off to the water heater.

• Use a wrench to disconnect the gas line to the old water heater.

• Inspect and detach the venting to the water heater.
• Set the venting aside. You'll use it later.

• Open a hot water faucet in your home, and let the water flow until it is cool.
• Shut off the incoming water supply to the water heater.

• Connect a garden hose to the drain valve.
• Open the drain valve and drain the tank.
• The water may contain sediment. If you have difficulty draining the tank, check out this article to help you unclog your drain valve. 
• Open a hot water faucet to allow air to enter the tank.

• Remove the T&P discharge pipe from the T&P valve.
• Set the discharge pipe aside. You'll use it later.

• Disconnect the water supply pipes.
• Remove the old water heater using a hand truck.

Step 2: Install the New Water Heater

• Place the new water heater in a drain pan.
• Install the discharge pipe to the T&P relief valve.

• Apply plumbers tape (white) to the hot and cold heat trap nipple threads.

• Attach the flexible hoses to the hot and cold water nipples.
• Use the dielectric fittings if required in your area.

• Use plumbers tape (white) to line each end of the connector body.

• Secure the flexible hose to one end of the connector body.

• Hold the other end of the hose up to the pipe and use a pencil to mark where to cut. Be sure to leave a little slack in the hose.

• Cut the pipe and remove the burs.

• Slide the compression nut onto the pipe.
• Push the pipe into the fitting and tighten the compression nut. 

• Install earthquake straps to secure the water heater to the wall.

Step 3: Fill the Water Heater Tank

• At the nearest faucet, remove the aerator and open the hot water side.
• Turn on the cold water supply to the water heater and check the fittings for leaks.
• If there are no leaks, fill the tank full of water.
• You'll know the tank is full when the water runs from the open faucet.
• Close the open faucet once the water stops sputtering.

Step 4: Attach the Venting and Gas Line

• Connect the venting to the water heater.

• Attach the venting to the exhaust hood using self-tapping sheet metal screws.

• Set the control knob to OFF on the water heater's control valve.

• Wrap the fitting threads with gas plumbers tape (yellow).

• Insert the flare nut into the control valve.

• Screw the other flare nut onto the gas line.

• Connect the flexible gas hose (yellow) to each flare nut.

• Turn the gas supply ON.

• Use leak detection solution on the gas fittings. The solution will bubble if there's a leak.
• Tighten connections as needed.

• Follow your manufacturers guidelines on how to light the pilot.
• Check that your water heater is properly venting.
• Install the air filter.

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