Gas safety guide · Klamath Falls, OR

Signs of a Gas Leak in Your House and What to Do

Signs of a gas leak in your house include a rotten-egg smell, a hissing sound and a dead patch of lawn. If you notice any, leave first and call from outside.

Emergency? Call now, 24/7(541) 407-8900
Cutaway of a home showing the plumbing systemWater main and sewer main under the street, a water heater in the garage, a toilet, a kitchen sink, drain lines and the sewer line. Numbered hotspots link to services.Water mainSewer mainWater heater1Drains2Leaks and pipes3Sewer line4Toilets and fixtures5
  1. Leave the houseEveryone out, no switches, no flames.
  2. Call from outside911 or the gas utility.
  3. Repair after the all-clearA plumber fixes the cause.
The short answer

The short answer on signs of a gas leak in your house

At a glance
  • A rotten-egg smellAdded odorant means gas may be escaping.
  • A hiss near a pipe or meterGas leaking under pressure makes noise.
  • Dead patch of grass or bubbles outdoorsA buried line may be leaking.
  • Headache and dizziness indoorsCould be gas or carbon monoxide.
  • What to doLeave, call 911 or the gas utility from outside.
What to look for

Signs of a gas leak in your house: what you may smell, hear and see

Gas leaks announce themselves in several ways. Any one of these is enough reason to act.

If you smell gas right now, leave first

Do not switch lights on or off, do not use a lighter or match, and do not look for the source. Walk out, take everyone with you, and call 911 or your gas utility from outside or from a neighbor’s house. Come back only when the utility or fire department says it is safe. Then read the rest of this page.

Your senses, one by one

Natural gas has no smell of its own. The utility adds a strong odorant that most people describe as rotten eggs or sulfur, so that a leak is noticed early. Propane carries a similar added smell. A faint whiff near the stove right after you light a burner can be normal, but a smell that lingers, spreads or comes back is not.

Sound and sight matter too. A leak from a pressurized pipe can hiss or whistle. Outdoors, a leak in a buried line can leave a patch of dead grass in an otherwise green lawn, bubbling in wet ground or standing water, or dirt that seems blown out of a spot. Indoors, flames that burn yellow or orange rather than steady blue point to a combustion problem that deserves attention.

Five kinds of warning
SenseWhat it may beTake it as
Smell: rotten eggs or sulfurAdded odorant escaping with gasA leak until proven otherwise
Sound: hissing or whistling near a pipe or meterGas escaping under pressureA leak; leave
Sight: dead patch of lawn, bubbles in wet groundA leak in a buried lineReport to the gas utility
Sight: yellow or orange burner flame, sootPoor combustionStop using the appliance, call
Body: headache, dizziness, nauseaGas or carbon monoxide exposureGet outside into fresh air
Signs of a gas leak in your house, by sense

Signs that are easy to miss

Some leaks are small and slow. A gas bill that climbs without a change in use, a pilot light that keeps going out, house plants that wilt for no reason, and a stove that clicks but lights oddly are all worth noticing. None proves a leak alone, but together they justify a check by someone with the right instruments.

Quiet signs
  • Smell that comes and goesSmall leaks vary with air movement.
  • A rising gas billMore gas used than the heating season explains.
  • Pilot lights that keep going outA sign of draft or supply trouble.
  • Houseplants dying near a linePossible leak at a buried pipe.
  • Headaches that ease outdoorsCould be gas or carbon monoxide.
What to do right now

What to do if you notice the signs of a gas leak in your house

Speed and order matter. These steps are written so anyone in the house can follow them.

Five steps, in this order

Gas is dangerous because a spark from almost anything can ignite it once the air mix is right. Your goal is to put distance between people and the leak, then let the people with the equipment handle it. You do not have to be sure it is a leak. Leave first and let the utility decide.

The call goes to 911 or to the gas utility’s emergency line, which is usually printed on your bill and on the meter. Make it from outside. Once the utility has checked the house and said it is clear, a plumber can repair the cause, and that is where our gas leak repair page comes in.

Your response plan
  1. Get everyone out

    Include pets. Leave doors open as you go if it is quick to do so.

  2. Do not touch switches

    No lights, no garage opener, no phone inside, no flame.

  3. Move away from the house

    Get well clear before you call.

  4. Call from outside

    911 or the gas utility’s emergency number.

  5. Stay out until cleared

    Only the utility or fire department can say it is safe.

What not to do

People get hurt by well-meant actions. Do not try to find the leak with a flame or by sniffing along pipes. Do not turn appliances on or off to see what changes. Do not open a gas valve, tighten a fitting or wrap tape on a connection. Gas work is a job for a person with the right tools and training, not a weekend task.

Do not do any of these
  • No flamesLighters, candles, matches, cigarettes.
  • No switchesLights, fans, garage door openers.
  • No phone calls insideWait until you are outside.
  • No re-entry to checkNot for a wallet, a pet or a pot on the stove.
  • No DIY pipe workLeave all gas repairs to a plumber.
A different gas

Gas leak or carbon monoxide: telling the two apart

They get confused often, and they need different responses. You may have either, or both.

Two different dangers

A natural gas or propane leak is unburned fuel escaping. Carbon monoxide is a byproduct of burning fuel, produced by a furnace, a water heater, a fireplace or a vehicle with a poorly vented exhaust. It has no smell at all, so the rotten-egg clue does not apply. It builds up in a closed house and poisons slowly.

The symptoms of carbon monoxide are headache, dizziness, nausea and confusion, often in several people at once, and they ease when you step outside. If a CO alarm sounds or if several people feel unwell with no other cause, get outside and call 911 as with a gas smell.

Two hazards
Gas leakCarbon monoxide
What it isUnburned fuel escapingA byproduct of burning fuel
SmellAdded rotten-egg odorNone
Main dangerFire and explosionPoisoning
DetectorA gas alarm, or your noseA CO alarm
First moveLeave, call from outsideLeave, call 911
Gas leak versus carbon monoxide

Alarms add protection while you sleep

A CO alarm belongs on every level and near sleeping areas, and the batteries should be tested on a regular schedule. Some homes also have a combustible gas alarm that responds to natural gas or propane. Alarms do not replace attention to the signs, but they work while you sleep.

Alarm basics
  • CO alarm near bedroomsTest it on a regular schedule.
  • CO alarm on each levelIncluding the basement.
  • Gas alarm near the furnace areaWhere fuel-burning appliances sit.
  • Replace on the date printedSensors wear out.
Where leaks come from

Common sources of a gas leak inside a home

Most leaks happen at joints and connections rather than along the middle of a pipe.

Fittings, connectors and appliances

Gas moves through black iron pipe, coated steel tubing or flexible corrugated lines, joined at threaded fittings, valves and appliance connectors. The weak points are the joints. A threaded joint can loosen over time. A flexible connector behind a stove, dryer or water heater can crack when the appliance is pushed back against a wall. A shutoff valve that has seen decades of use can start to weep at its stem.

Corrosion is a second source, especially in damp places or on older steel pipe. Damage from remodeling is a third: a nail or screw into a wall that holds a gas line, or a tool through a buried run. Gas line repair deals with the pipe itself, and a leak at an appliance connection is usually a short repair once the area is safe.

Typical sources
Where it leaksCommon cause
Appliance flexible connectorKinked or cracked when the appliance moved
Shutoff valve at the applianceWorn stem or seat
Threaded pipe jointLoosened or corroded fitting
Pipe inside a wall or ceilingCorrosion or a fastener driven through
Buried line outsideCorrosion, shifting ground or digging damage
Appliance itselfFailed gasket, burner or gas valve
Where gas escapes in a house

Old appliances and new work

Older stoves, heaters and water heaters can have worn gas valves and burners, and any appliance that is moved or replaced gets a new connection that must be tested. If the signs appear after someone installed or serviced equipment, mention it on the call. A leak right after new work is useful information.

Before any digging on your property, call 811 so buried utility lines are marked. This is general advice anywhere in the country and it protects you from a strike on a gas line.

When risk goes up
  • After an appliance installConnections need a leak check.
  • After a remodelHidden lines may have been disturbed.
  • Before digging a fence or gardenCall 811 for line marking.
  • After moving a stove or dryerCheck the flexible connector.
Cold-season angle

Why gas safety matters more during cold weather

Furnaces and water heaters work hardest in a long winter, and the signs of a problem are easier to miss indoors.

More burning, less fresh air

In a high-desert basin where the heating season runs long, gas appliances run for months. That is more hours of combustion, and doors and windows stay closed, which means a small leak or a venting fault has less fresh air to dilute it. Pilot lights can be blown out by drafts in cold garages and utility closets, and then gas can flow until the thermocouple shuts it off.

Check that exhaust vents and intake pipes are clear of snow and ice, since a blocked vent pushes combustion gases back into the house. Space heaters that burn fuel also need ventilation and are not for sleeping areas. If you are away for part of winter, check that the heating system is still working before the cold hits, a theme also covered in how to prevent frozen pipes.

Winter gas checklist
  • Vents clear of snow and iceFurnace, water heater and dryer.
  • Garage heater and water heater areaDrafts can blow out pilots.
  • Fuel-burning space heatersVentilate and keep away from beds.
  • Alarms tested before the coldCO and gas alarms.
  • Furnace serviced before heating seasonBurners and venting checked.

Gas water heaters get special attention

A gas water heater sits close to the ground, in a closet or garage, with a burner, a vent and a gas valve. Rust at the bottom, soot around the draft hood, a smell of burning or a flame that wobbles are all warning signs. The water heater repair page covers diagnosis, and if the unit is aged, water heater replacement covers the next step. A gas appliance with a vent problem should be shut down until it is checked.

Heater warnings
WarningWhat to do
Soot or scorch marks around the heaterStop using it; call
Burner flame yellow or flickeringCall for a combustion check
Smell of exhaust in the roomOpen doors, leave if strong, call
Pilot out repeatedlyDo not keep relighting; call
Gas water heater warning signs
After you get out

What happens once the gas utility has cleared your house

The emergency ends when the utility says it does. The cause still needs finding and fixing.

From the all-clear to a safe repair

The utility or fire department will check the meter and the air, may shut off the gas supply and will tell you when you can go back in. If the leak is on the utility’s side of the meter, they repair it. If it is inside your house, it is yours to fix, and the gas stays off until a plumber has found the leak, repaired it and tested the system.

Expect the plumber to look at appliance connections first, then valves and exposed pipe, and to use a pressure test on the system when the source is not obvious. They will also say whether the repair is a connector, a valve or a section of pipe. Only after the testing is done should the gas be turned back on and appliances relit by someone qualified.

From emergency to repair
  1. Utility or 911 clears the home

    You are told when you can re-enter.

  2. Gas stays off

    Until the leak source is repaired.

  3. Plumber finds the source

    Connections, valves, then pipe and pressure test.

  4. Repair and test

    The system is proven tight before use.

  5. Gas back on, appliances relit

    Done by someone qualified.

What affects the repair

A loose appliance connector is a short job. A leaking valve, a corroded section or a damaged buried line is larger. Access matters: a line behind a finished wall or buried under a patio takes more work than one in an open basement. Ask about pricing when you call, and describe what the utility found.

Information that helps
  • What the utility foundWhich side of the meter.
  • Which appliance or areaWhere the smell is strongest.
  • Age of lines and appliancesHelps the plumber plan.
  • Any recent work in the houseNew work is a useful clue.
Prevention

How to lower the chance of a gas leak at home

No home is risk-free, but a few habits catch problems early.

Habits that catch trouble early

Know where your gas meter and shutoff are and teach everyone in the house to recognize the smell. Have furnaces and fuel-burning heaters serviced before each heating season. Keep storage and clutter away from heaters and water heaters. Inspect flexible connectors for kinks or cracks whenever an appliance is moved.

When you add a new gas appliance, such as a range, a dryer or a heater, have the hookup done and tested by a plumber. For a tankless unit see tankless water heater, which needs a correctly sized gas line. For general repairs, plumbing repair covers the wider job list, and emergency plumber is there if a problem cannot wait.

Regular habits
HabitHow often
Test CO and gas alarmsOn a regular schedule, and after any power outage
Furnace and heater serviceBefore each heating season
Check flexible connectorsWhenever an appliance is moved
Look for rust or soot at the water heaterA few times a year
Call 811 before diggingBefore every dig
Prevention at a glance

Know who to call

For the smell of gas: 911 or the gas utility. For a repair after the all-clear: a plumber. For a suspected CO problem: 911. Write the utility’s emergency number on a card near the door. If you have other questions about your system, our how to choose a plumber guide helps you pick who to call for the repair.

Order of calls

Keep it simple

In any gas emergency the first call is not to a plumber. Get out, call 911 or the utility from outside, and let the plumber come after the all-clear.

When to call

When a gas problem needs a plumber after the all-clear

The utility handles the emergency. A plumber handles what is wrong inside your walls.

  1. The utility found a leak on your side

    Everything past the meter is yours to repair.

  2. An appliance connector looks damaged

    Kinked, cracked or corroded lines need replacing.

  3. A new gas appliance is going in

    Hookups should be tested before use.

  4. The smell keeps returning

    A slow leak can be hard to find without instruments.

Questions

Questions about the signs of a gas leak

What are the signs of a gas leak in your house?

A rotten-egg or sulfur smell is the main one. Others are a hissing sound near a pipe or appliance, dead plants over a buried line, bubbles in wet ground, yellow or orange burner flames, and headaches or dizziness that ease outdoors. Any of these means leave and call.

What should I do first if I smell gas?

Get everyone out of the house. Do not touch light switches, use flames or look for the leak. Move away from the house and call 911 or the gas utility from outside or from a neighbor’s. Stay out until you are told it is safe.

Should I open windows before I leave?

Only if it takes a moment and you are already moving toward the door. Do not spend time on it, and do not switch on a fan. Getting people out is the priority, and the utility or fire department will ventilate when they arrive.

Can I turn off the gas myself?

Leave it to the gas utility. They shut off supply at the meter and know how to do it safely. Trying to handle valves in a gassy house is a risk, and the smell is reason to be outside, not at the meter.

Is it okay to use my phone in the house?

Make the call from outside. The risk from a phone is small, but with an unknown amount of gas in the air, the rule is to avoid anything that could spark until you are clear of the building.

How is a gas leak different from carbon monoxide?

A gas leak is unburned fuel with an added rotten-egg smell. Carbon monoxide comes from burning fuel and has no smell. Gas risks fire; CO risks poisoning. Both mean get outside and call 911. A CO alarm detects the second, a gas alarm the first.

Who fixes a gas leak after the utility has cleared the house?

The utility repairs problems on its side of the meter. Leaks in the house piping or at your appliances need a plumber. See gas leak repair and gas line repair. The gas stays off until the repair is tested.

What causes a gas smell near the stove right after I light it?

A brief smell as a burner lights can be a little unburned gas. If it lingers, returns or you smell it when nothing is on, treat it as a leak. If one burner will not ignite cleanly, stop using it and have it checked.

How much does a gas leak repair cost?

It depends on the source. A worn connector is a small job, a leaking valve or a corroded section is more, and a buried line costs most because of access. Ask about pricing when you call, and tell us what the utility found.

Can I get a plumber the same day for a gas problem?

Same-day service is available and the line is open 24/7. But for a smell of gas, the first call is 911 or the gas utility from outside. A plumber comes next, once the utility or fire department has cleared the house.

Gas repairs start after the all-clear

Leave first and call 911 or the gas utility from outside. When it is safe, call us for the repair. Open 24/7. Ask about pricing when you call.

Call now, 24/7(541) 407-8900