How to Turn Off the Gas to Your Water Heater

Needing to turn off the gas to your water heater is a fairly common task for homeowners. Whether you are doing maintenance, repairs, or replacing your unit, knowing how to safely shut off the gas is an important skill. We will walk through the step-by-step process to turn off the gas supply to your water heater.

Locate the Gas Shutoff Valve

The first step is locating the shutoff valve for the gas line that runs to your water heater. This is usually a knob or lever found on the pipe leading into the unit.

  • Common locations for the gas valve are:
    • On the gas supply pipe directly before it enters the water heater
    • Near the wall behind the water heater
    • By the meters outside of the home
    • In the basement, garage, or utility area
  • The shutoff valve should be clearly labeled and easy to access
  • If you cannot find the valve, refer to your unit’s manual or contact the manufacturer

Once you have located the gas shutoff valve for your water heater, proceed to the next step.

Turn the Gas Shutoff Valve

With the proper gas shutoff valve located, you are ready to turn off the gas.

  • Place a wrench or adjustable pliers on the valve knob/lever
  • Turn the valve a 1⁄4 turn until it is perpendicular to the pipe (the lever will form a “T” with the pipe)
  • Double check that the valve is now turned fully off

Turning the valve a 1⁄4 turn closes it off and stops gas from flowing to the water heater. Be sure the lever is positioned crosswise to the pipe to verify gas supply is cut off.

Check for Gas Flow

Before working on your water heater, check to make sure shutting off the valve fully stopped gas flow.

  • Remove the outer burner door on your water heater
  • Examine the pilot light – it should be extinguished
  • For units with standing pilots, press the pilot valve – you should not smell gas
  • If you detect gas, turn the main valve back on and call a professional

If no gas smell or flow is detected, proceed with maintenance or repairs knowing the fuel line has been safely shut off.

Turn Gas Supply Back On

Once your work on the water heater is complete, you can restore the gas supply:

  • Confirm all repairs, replacements, or maintenance is fully finished
  • Verify no gas smell is present
  • Return the gas shutoff lever to its open, parallel position
  • Check that pilot flames are lit and burners ignite as expected
  • Test for leaks by brushing soapy water on connections – bubbles indicate leaks

With gas flowing safely to the water heater again, you can relax knowing you successfully shut off and restored fuel to your unit.

When to Call a Professional

While the basic gas shutoff process is straightforward, there are times to call a pro:

  • If you cannot locate the shutoff valve
  • If gas continues flowing even after turning off the valve
  • If the valve or piping is damaged
  • For suspected leaks, irregular burner operation, or other problems

Gas work should only be done by qualified technicians for your safety.

FAQs About Shutting Off Water Heater Gas

Turning off the gas supply to your water heater may seem daunting. Here are answers to some frequently asked questions:

How do I know if I successfully shut off the gas?

You can test by pressing the pilot valve or checking if pilot/burner flames are extinguished. If gas continues flowing, call a professional.

Do I need to shut off the water too?

If doing repairs that expose water pipes, yes. Otherwise shutting gas off is sufficient.

Is it safe to shut off gas at night/for vacation?

Yes, as long as you restore proper gas service after. Don’t leave off too long.

What if I can’t find the right shutoff valve?

Trace lines from heater or call the manufacturer. Don’t mess with any gas lines until valve is found.

How can I tell if a valve or piping is damaged?

Look for corrosion, dents, kinks, or loose fittings. Any issues should be handled by a professional.

What should I do after the gas is back on?

Double check for leaks, test ignition, and monitor flames/pilot lights for a while to ensure proper operation.

Why does my pilot keep going out after I turn gas back on?

Air in pipes needs bled out. Relight pilot, let run 15+ minutes before re-lighting if needed. Call for help if issue persists.

Is it safe to turn water heater gas off/on myself?

Yes, if you follow proper safety procedures. When in doubt, call a licensed plumber or gas technician.


Learning how to safely turn off the gas to your water heater is an easy yet critical skill for homeowners. By locating the shutoff valve, completely cutting off gas flow, performing work, and restoring service, you can maintain your unit with confidence. While calling a professional is recommended for any complex gas work, you can feel empowered knowing how to shut off and turn back on gas when needed. Just be sure to take precautions, work safely, and light pilots properly when finishing up. With the right preparation and care, you can handle shutting off your water heater gas supply successfully.