Short answer
Leave the building now, on foot, and take everyone with you. Do not flip switches, light anything, start a car or use a phone inside. Once you are well away, call your gas utility's emergency line or 911. Do not go back in or try to find or fix the leak. Wait for the utility to say it is safe.
Key facts
- CenterPoint Energy tells customers who smell gas to leave immediately on foot and not to use a cell phone, start a car, or do anything that could cause a spark.[1]
- CenterPoint's guidance: once safe, call the utility and 911, and never try to locate or fix a gas leak yourself.[1]
- Gas appliance manuals, such as Navien's NPE-2 manual, carry the same warning: do not light any appliance or touch electrical switches, and call the gas supplier from a neighbor's phone.[2]
Do this now
- Get everyone out. Leave on foot. Leave doors as they are. Take pets if you can do it without delay.
- Do not create a spark. Do not turn lights or appliances on or off, do not use a phone, do not light a match or lighter, and do not start a car in an attached garage[1].
- Call from a safe distance. Once you are well away from the building, call your gas utility's emergency number and 911[1]. If you do not know the utility number, 911 is enough.
- Warn neighbors if it is safe to do so, and keep people away[1].
- Stay out until the utility or fire department says it is safe. Do not try to find or fix the leak yourself[1].
Manufacturer manuals for gas water heaters print the same instructions on their safety pages: do not try to light any appliance, do not touch electrical switches, and call the gas supplier from a neighbor's phone[2].
Why we will not give you troubleshooting steps here
Natural gas and propane leaks can ignite from a single spark. The steps above are the same ones gas utilities and appliance makers give. There is no water heater check worth the risk of staying inside.
Propane customers: call your propane supplier's emergency line and 911 from outside.
After the all-clear
The utility will typically find the source, shut off gas to the affected appliance or the whole house, and may leave a tag on the appliance or meter. Gas is restored only after the problem is repaired.
- If the leak was at the water heater, a licensed plumber needs to repair the gas connection, the gas control valve or the heater before gas is restored. On an older tank, this is often the point to replace it. See repair or replace.
- Do not relight the pilot yourself after a leak. Let the plumber or the utility do it once the repair is done.
- Add or test carbon monoxide alarms. Gas leaks and venting problems are different hazards, but a visit like this is a good time to check both. See carbon monoxide and back-drafting.
When to call a pro
- Any gas smell near the heater: the gas utility or 911 first, from outside.
- After the utility tags the water heater: a licensed plumber for the repair.
- A smell of exhaust, soot, or scorch marks near the burner door (possible venting problem).
More questions
The smell is only in my hot water, not the air. Is that a gas leak?
A sulfur smell that comes out of the hot tap is usually a reaction inside the tank, not a gas leak. See our rotten egg smell page. If you smell it in the air near any gas appliance, treat it as a leak.
Should I turn off the gas valve on the water heater before I leave?
No. Do not stay inside to work on valves. Get out first. The utility's responders will shut off and check the gas.
Sources
- What to do if you smell natural gas, CenterPoint Energy. Accessed 2026-10-06.
- NPE-2 User's Information Manual (2020-12), safety warnings, Navien. Accessed 2026-10-06.
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