How to Install a Water Heater Gas Valve

What You'll Need
Garden hose
Detergent solution
New Gas Valve
Teflon Tape

A faulty water heater gas valve can lead to heating problems and can prevent your heater from functioning properly. Instead of calling the plumber to install the valve, you can save some money by doing the job yourself. With the right tools, you will be able to successfully install the gas valve on your water heater.

Step 1 - Shut Off the Water Supply

To shut off the water supply, find the knob above the heater on the incoming water pipe and turn it off.

Step 2 - Shut Off the Gas Supply

You can stop the gas supply by turning off the gas pipe located next to the gas valve.

Step 3 – Ensure the Gas is Turned Off

Place your finger over the opening of the gas line. If you feel a breeze, it means the gas is not completely turned off and you need to properly shut off the gas supply.

Step 4 - Drain the Water

The heater will have some quantity of water stored. To drain the water heater attach a garden hose to the valve at the bottom of the tank. The drained water will be hot and rusty so make arrangements to discard it. Adjust the drain valve to break the vacuum.

Step 5 - Disconnect the Gas Flex Hose

After the heater is completely drained use a wrench to disconnect the gas flex hose. A flex hose is connected to the gas valve and looks like a cord.

Step 6 - Disconnecting the Three Tubes

Look for three tubes entering from the bottom of the gas valve. These tubes have to be disconnected. Loosen the nuts connected to the gas valve and pull the tubes out. 

Step 7 – Remove the Gas Valve

At this point the gas valve is ready to be unscrewed from the heater. You might need to apply more force to the wrench to loosen the screw as it has been untouched for a long time.

Step 8 – Determine the Length of the Shank

A shank is a threaded nipple that connects the valve and the tank. Measure the length of this shank. It typically comes in two measurements 3/8 inches and 2-3/8 inches

Step 9 – Buying a Gas Valve

While buying a new water heater gas valve make sure to take the shank measurement along. The shank should be of the same length otherwise it will not accommodate the three tubes.

Step 10 – Install the New Valve

Put the new gas valve in place, screw it in tight, connect the three tubes and the gas flex hose, open the water and gas supply.

Step 11 – Check for Leaks

After installing the valve check for leaks by spraying a detergent solution on the fittings, if there are bubbles there is a leak. Wind Teflon tape around the shank and seal any leak.

Step 12 – Check the Water Heater

Turn on the water and gas supply and check your water heater it should be working fine.