I smell gas faintly. Should I call the utility or wait?

Leave the building and call from outside. Utilities treat suspected leaks as emergencies and will respond — they would far rather check a false alarm than be called after an incident.

Can I connect my own gas range or dryer?

No. Appliance gas connections are regulated work in most jurisdictions and a failed connection can leak into a closed home. Use a licensed professional.

What's the difference between a gas leak and carbon monoxide?

A gas leak is unburned fuel escaping, and the added odorant makes it noticeable. Carbon monoxide is a product of incomplete combustion, is odorless and invisible, and is detected only by alarms. Both are emergencies; both need everyone out of the building and professional help.

Gas

Gas Line Problems: Safety First, Always

A suspected gas leak or a problem with gas piping or appliances. This is one category where there is no homeowner repair.

A homeowner guide — what may be happening, and what to do next.

If this is an emergency

Uncontrolled water, sewage entering the home, a suspected gas leak, or water near electrical equipment all need immediate action. Shut off the water at the main if it is safe to reach, keep everyone away from hazards, and contact your local emergency services, your utility provider, or a licensed professional as appropriate.

What's happening?

Natural gas and propane are delivered under pressure to appliances through piping that must be correctly sized, correctly joined, properly supported, and pressure-tested. Because leaking gas can accumulate and ignite, and because incomplete combustion produces carbon monoxide, gas work is regulated almost everywhere and requires a licensed professional — often with a specific gas qualification beyond a general plumbing license.

Utilities add a distinctive rotten-egg odorant to gas so leaks can be noticed. That smell is the signal to leave, not to start investigating. Carbon monoxide, by contrast, has no smell at all — which is why working CO alarms matter in any home with gas appliances.

We are deliberately not describing how to test, repair, or modify gas piping on this page. There is no version of that work that belongs to a homeowner.

Common signs

Symptoms homeowners notice

A rotten-egg or sulfur smell indoors or outdoors near the meter
A hissing or blowing sound near a gas line, meter, or appliance
Dead or discolored vegetation in a line over a buried gas line
Soot, scorching, or yellow rather than blue flames on a gas appliance
A pilot light that repeatedly goes out
Headaches, dizziness, nausea, or drowsiness that improve when you leave the house
A carbon monoxide alarm sounding
Gas appliances that don't perform as they used to

Possible causes

From simple to more serious — not a diagnosis of your specific situation

A failed joint, fitting, or connector: Age, corrosion, vibration, or a flexible appliance connector past its life.
Corroded piping: Particularly where piping is buried or exposed to moisture.
Physical damage: Excavation, movement, or impact to buried or exposed piping.
Improper past work: Unpermitted or incorrect installation, wrong materials, or unsupported piping.
Appliance or control faults: Gas valves, burners, and regulators can fail internally.
Undersized piping: Not enough gas volume for the appliances connected, causing poor performance.
Venting problems: Blocked or failed venting is a carbon monoxide risk rather than a leak risk, and just as serious.

How urgent is it?

Emergency — act now on safety

If you suspect a gas leak, leave the building immediately and call your gas utility's emergency number or emergency services from outside. Do not investigate.

Low
Medium
High
Emergency

What you can safely check

Simple observations and low-risk checks. None of these require tools you don't have or work you aren't qualified for.

If you smell gas: leave the building immediately, taking everyone with you.
From outside and well away from the building, call your gas utility's emergency number or your local emergency services.
Don't use light switches, appliances, garage door openers, or phones inside the building.
Leave doors open as you exit if you can do so without delay.
Wait outside, and don't go back in until the utility or emergency responders say it's safe.
In non-emergency conditions: confirm you have working carbon monoxide alarms on each level and near sleeping areas.
In non-emergency conditions: note appliance flame color, soot, or performance changes and describe them to a licensed professional.

What not to do

These are the actions that turn a manageable problem into an expensive or dangerous one.

Avoid these

Don't look for the leak yourself. No soap test, no sniffing along pipes, no opening cabinets.
Don't operate any electrical switch, light, appliance, phone, or vehicle in or near a suspected gas accumulation. A switch spark is an ignition source.
Don't light a match, lighter, candle, or any flame.
Don't attempt to repair, tighten, cap, tape, or modify gas piping or fittings.
Don't reconnect or move a gas appliance yourself, including a range or a dryer.
Don't run gas piping for a new appliance, grill, fire pit, or generator as a DIY project.
Don't ignore a CO alarm or reset it and go back to sleep. Get everyone out and call for help.
Don't use unvented gas appliances as space heaters in enclosed living areas.
Don't assume a smell that fades means the problem resolved.

Can I fix this myself?

Safe to check

Observation and low-risk checks most homeowners can make.

Leaving the building and calling for help from outside
Keeping everyone away until responders clear the property
Installing and testing carbon monoxide alarms
Noting appliance symptoms to describe to a professional

Proceed with caution

Minor actions where instructions must be followed carefully.

Nothing in this category for this problem.

Call a professional

Regulated, hazardous, or specialized work. Don't attempt it.

All gas leak investigation and repair
All gas piping installation, modification, and pressure testing
Gas appliance connection, replacement, and venting
Gas pressure and sizing assessments
Anything at all involving gas

When to call a licensed plumber

Clear signals it's time for professional help

Immediately, from outside, for any suspected gas leak — call the utility's emergency line or emergency services
Immediately if a carbon monoxide alarm sounds or anyone has symptoms
Before installing, moving, or reconnecting any gas appliance
When a gas appliance shows soot, yellow flames, or repeated pilot outages
When you're planning work that requires new or modified gas piping
When buying a home and you want the gas system assessed

Not sure yet? Read our general guidance on when a plumber is needed.

Questions to ask your plumber

Worth covering before you authorize any work.

Before work starts

1Are you licensed and specifically qualified for gas work in this jurisdiction?
2Will this work be permitted and inspected?
3Will the piping be pressure-tested, and can I see the results?
4Is my existing gas piping correctly sized for the appliances connected?
5Has the appliance venting been checked as well as the gas supply?
6Are my carbon monoxide alarms adequate and correctly placed?
7Are you licensed to do this type of work in my area, and can I see your license number?
8Do you carry liability insurance and workers' compensation?
9Will you provide a written estimate before starting work?
10Is a diagnostic or trip fee charged, and is it applied to the repair if I go ahead?
11Does this work require a permit or an inspection?
12What warranty applies to the labor, and what warranty applies to the parts?

What could affect the cost?

We don't publish prices, because real quotes depend on your home, your area, and what's found on site. These are the variables that move the number.

Cost drivers

Licensing and qualification: Gas work requires specific credentials, which is reflected in labor rates.
Permits and inspection: Commonly required for gas work; fees and process vary by jurisdiction.
Testing and diagnostics: Pressure testing and leak locating take time and equipment.
Length and routing of piping: New runs, upsizing, and concealed routing all add labor.
Excavation: Buried line repair involves digging, locating other utilities, and surface restoration.
Appliance work: Repair or replacement of gas appliances and their venting is separate from piping work.
Emergency response: Emergency gas response is prioritized and priced accordingly.

More detail on how plumbing work is priced: Plumbing costs — what to expect.

Common questions

I smell gas faintly. Should I call the utility or wait?: Leave the building and call from outside. Utilities treat suspected leaks as emergencies and will respond — they would far rather check a false alarm than be called after an incident.
Can I connect my own gas range or dryer?: No. Appliance gas connections are regulated work in most jurisdictions and a failed connection can leak into a closed home. Use a licensed professional.
What's the difference between a gas leak and carbon monoxide?: A gas leak is unburned fuel escaping, and the added odorant makes it noticeable. Carbon monoxide is a product of incomplete combustion, is odorless and invisible, and is detected only by alarms. Both are emergencies; both need everyone out of the building and professional help.

This guide is general educational information, not a diagnosis of your specific situation. Plumbing codes, regulations, and licensing requirements vary by state and locality.