The short answer
First Steps to Take
If you smell that rotten-egg odor, do not ignore it. Leave the house right away, and do not flip any light switches, use your phone, or light a match. Once you are safely outside, call your gas utility's emergency number or the fire department. They can check for leaks and shut off the gas if needed.
Do not try to find the leak yourself. Gas leaks can be dangerous, and the pros have the right tools to detect them safely. While you wait outside, keep everyone away from the building. If you have a gas shutoff valve, only turn it if you know how and it is safe to reach.
Other Possible Causes
That gas-like smell is not always natural gas. A sewer line backup or a dried-out drain can produce a similar odor, especially in warmer weather. A dead animal in a wall or crawl space can also smell like something rotting, which might be mistaken for gas. Some paints, adhesives, and cleaning products can release fumes that smell like gas too.
If the smell is faint and comes and goes, check your drains first by running water through each one. If the odor is strong and constant, treat it as a real gas leak. Your nose is a good detector, but a professional leak detection service can pinpoint the exact source.
- Rotten egg smell from natural gas additive
- Sewer gas from a clogged or dry drain
- Dead animal in walls, attic, or under the house
- Chemical fumes from paint, glue, or solvents
- Propane leak from a tank or appliance
- Mercaptan odor from a gas line that is not lit
When to Call the Pros
The fire department or your gas utility is the first call for a suspected gas leak. After the immediate danger is handled, you may need a plumber or a leak detection service to find and fix the source. For example, a pipe leak behind a wall or under the floor can release gas slowly, and it takes special equipment to locate it.
If the leak is from an appliance like a stove, water heater, or furnace, the pros can inspect the connection and the line. They can also check for water damage that might have corroded a gas line, especially in damp climates where moisture can cause rust. Acting quickly can prevent a small issue from becoming a bigger problem.
Preventing Future Odors
Regular maintenance can reduce the chance of a gas leak. Have your gas appliances and lines inspected periodically, especially if you live in an older home. Keep the area around your gas meter and shutoff valve clear, and know where the valve is located in case of an emergency.
If you have a sewer smell, keep drains clear and run water regularly to keep the traps filled. For dead animal odors, you may need to locate the source and remove it, which sometimes requires cutting into a wall. In that case, a water damage professional can help with the cleanup if the animal caused any mess.
A little preparation can save time and stress later.
What About Water Damage?
A gas leak is not water damage, but water can cause gas line corrosion over time. If a pipe leak or a flood has soaked the area near a gas line, the metal can rust and develop small holes. That is why it is important to address water leaks quickly and dry out the affected areas.
If you have had water damage and now smell gas, the two issues might be related. The pros can inspect both the water damage and the gas line to see if there is a connection. They can also help with structural drying and dehumidification to prevent mold and further damage to your home.
Even if the smell is not gas, a persistent odor might indicate hidden moisture or rot. A water damage inspection can uncover issues you cannot see, helping you keep your home safe and comfortable.
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Call Now (425) 407-5186Frequently asked questions
What does a gas leak smell like?
Natural gas is odorless, but the utility adds a chemical called mercaptan to give it a strong rotten egg or sulfur smell. Propane also has a similar odor added. If you smell that, it is a sign of a leak, even if it is faint.
Can a gas leak cause water damage?
No, a gas leak itself does not cause water damage. But water leaks can corrode gas lines and fittings, leading to a gas leak. If you have had a water leak, it is wise to check the nearby gas lines for damage.
Should I open windows when I smell gas?
Open windows and doors as you leave the house, but do not stay inside to do it. The goal is to ventilate, but your safety comes first. Leave the building and call for help from outside. Do not turn on any fans or lights.