If you smell gas or otherwise suspect a fuel-gas leak, treat it as a potential emergency. This is not the time to locate the exact fitting, test an appliance, or search the house for the source.
Leave the building
Get people out and move to a safe location away from the suspected leak. Follow the emergency instructions provided by your local gas utility and public-safety authorities.
Avoid ignition sources
Do not light matches, smoke, or create a flame. Avoid operating switches, appliances, or other equipment in the suspected area when doing so could create an ignition source. Do not remain inside to troubleshoot.
Call from a safe location
Contact the gas utility’s emergency number or emergency services as directed for your location. Give them the address and describe what you noticed. Follow their instructions about where to wait and when it is safe to return.
Do not assume the smell disappearing means the problem is gone
Odors can change with airflow and conditions. Let qualified utility or emergency personnel determine whether the area is safe and what needs repair.
Carbon monoxide is a different warning problem
Carbon monoxide cannot be detected by smell. Maintain working carbon monoxide alarms where recommended or required and follow the alarm manufacturer’s and local emergency guidance if an alarm sounds.
For future reference: save your gas utility’s emergency contact information in your phone before you need it.
This is emergency-safety information, not repair guidance. Utility procedures vary by location. If you suspect a gas leak, leave the area and follow your local gas utility or emergency authority’s instructions.