Plumbing guide · Lakeville, MN
Signs of a Gas Leak in Your House and What to Do
Know the signs of a gas leak in your house before you need them. If you smell gas, leave first and call from outside; this page explains what to look for and what happens next.
Emergency? Call now, 24/7(952) 000-0000- Leave right awayDo not switch anything on or off.
- Call from outsideGas utility emergency line or 911.
- Stay out until clearedThen call a plumber to repair the cause.
Signs of a gas leak in your house: the short answer
- A sulfur or rotten-egg smellLeave at once, call from outside.
- A hiss near a pipe, meter or applianceGas is escaping under pressure.
- Headache, dizziness or nausea indoorsEspecially if it eases outside. Leave and call 911.
- Dead plants or bubbling water outdoorsA buried line may be leaking.
- Do not use switches, flames or indoor phonesA spark can ignite gas.
Signs of a gas leak in your house: what you smell, hear and see
Natural gas has no scent of its own. The smell people recognize is an additive, and it is only one of several clues.
The odor and the sounds
Gas suppliers add a sulfur-like odor so a leak is noticed. People describe it as rotten eggs, a struck match or a sulfur sink. It may be strongest near an appliance, a meter or a pipe joint, or it may drift through the whole house. A leak can also be loud enough to hear: a steady hiss near a pipe, a regulator or a fitting means gas is moving where it should not.
Smell can fade. Some people lose the ability to notice the odor, and in rare cases the scent weakens as gas passes through soil or other materials. Treat any suspicion as real, and do not decide it is gone because you stopped noticing it.
| Sense | What it may be | What to do |
|---|---|---|
| Rotten-egg or sulfur smell | Gas escaping inside or outside | Leave at once and call from outside |
| Steady hiss near a pipe or meter | Gas moving through a damaged fitting | Leave and call from outside |
| Whistling near a gas appliance | A leak at a valve or connector | Leave and call |
| Bubbling in standing water outdoors | Buried gas line leaking | Move away, call from a safe distance |
| Dirt blowing up from the ground | High-pressure line damage | Leave the area, call 911 |
What you might see
Outdoors, a leaking buried line can kill grass and shrubs in a dead patch with no other explanation, even when the rest of the lawn is green. Snow can melt in an odd spot above a leak. Indoors, a gas range or furnace burner that burns orange or yellow instead of steady blue is a sign of incomplete combustion, which is a separate danger. A pilot light that keeps going out may point to a draft, but a gas smell with it is a reason to leave.
- Dead or yellow patch above the linePlants killed by gas in the soil.
- Bare spot in snow over a pipeWarmth or a leak affecting the melt.
- Yellow or orange burner flamePoor combustion; have the appliance checked.
- Pilot lights that keep dyingDraft, dirty orifice or a failing valve.
- Soot marks around an applianceIncomplete burning and possible carbon monoxide.
What to do if you smell gas: leave first, then call
Do not try to find the leak yourself. Your only job is to get out and let trained responders handle the rest.
Stop what you are doing
Do not switch lights or appliances on or off, do not use a lighter, candle or match, and do not start a car in an attached garage.
Get everyone out
Take children, pets and anyone nearby outside. Leave the door open behind you if it is safe to do so, and do not stop for belongings.
Move away from the building
Walk well clear. Gas can pool in low spots, so stay upwind and away from vehicles and drains.
Call from outside
Use your cell phone from a safe distance, or a neighbor’s. Call your gas utility’s emergency number, or 911 if you are unsure or someone feels ill.
Wait for the all clear
Do not go back in until the utility or fire department says the building is safe, even if the smell has faded.
Call a plumber after clearance
Once responders clear the building, a plumber can find and fix the leak. Do not relight appliances yourself.
No home steps for gas
Do not try to tighten a fitting, patch a pipe or shut off valves hunting for the leak. Using any phone or switch inside can create a spark. Get out first. Your gas utility’s emergency number is printed on your bill, and 911 works if you cannot find it.
Signs of a gas leak in your house that show up in your body
A leak you cannot smell can still affect people. Know the difference between a gas leak and carbon monoxide.
Symptoms to take seriously
People in a home with a significant gas leak may feel headaches, dizziness, nausea, tiredness or trouble breathing. Pets can show it first. These are not specific to gas, but if they come on indoors, ease when you step outside, and come with any odor or hiss, treat them as an emergency and leave. Do not wait to see whether you feel better.
- Headache or dizziness indoorsBetter outside is a strong hint.
- Nausea or fatigue for several people at onceShared symptoms point to the house.
- Pets acting oddly or collapsingAnimals often react sooner.
- Nosebleeds or breathing troubleLeave and call 911.
- Symptoms that vanish when you leaveA signal that something in the house is wrong.
Gas leak or carbon monoxide?
Carbon monoxide is a different hazard. It is produced when fuel burns without enough air, from a furnace, water heater, range or generator, and it has no smell at all. The two share symptoms, so the safe move is the same: leave, call from outside and get the home checked. A working carbon monoxide alarm gives a warning that your nose cannot. Test yours often and replace it on the maker’s schedule.
| Natural gas leak | Carbon monoxide | |
|---|---|---|
| Source | Escaping fuel from a line or appliance | Exhaust from burning fuel |
| Smell | Added sulfur odor | None |
| Detector | Gas alarm, your nose | CO alarm only |
| Main danger | Fire, explosion, low oxygen | Poisoning |
| First action | Leave, call from outside | Leave, call 911 |
Where a gas leak in your house usually starts
Knowing the common sources helps you describe the problem when you call.
| Place | Why it fails | How you might notice |
|---|---|---|
| Range or cooktop connector | Flexible connector bent or worn when the appliance is moved | Smell near the back of the stove after cleaning |
| Furnace or boiler gas valve | Seals dry out with age | Odor in the utility room, especially when the burner starts |
| Water heater gas line | Loose union, damaged flex line | Smell near the heater; see water heater repair |
| Gas dryer connection | Kinked flex line behind the machine | Odor in the laundry room |
| Pipe joints in walls and basements | Fitting loosened by settling or vibration | A hiss or an area-wide smell |
| Meter and regulator outside | Damage from ice, impact or digging | Odor outdoors near the meter |
| Buried line to the house | Corrosion, shifting, digging damage | Dead plants, bubbling in wet ground |
| Fireplace and outdoor grill lines | Cracked hose, loose valve | Hiss or smell near the unit |
Gas piping repair is specialist work. After the area has been cleared by the utility, a plumber can test the lines and fix the cause. Our pages on gas leak repair and gas line repair explain how the work goes. Ask about pricing when you call.
Signs of a gas leak in your home during a Minnesota winter
Heating season puts the most demand on your gas system, so winter is when problems show up.
Furnace, meter and snow
Furnaces run for long stretches in winter, which stresses burners, valves and connections. The outdoor meter and regulator can be damaged by falling ice from a roof or buried under snow where a plow or blower might strike them. Keep the meter and its surroundings clear by hand, and do not use a sharp tool near it. If a roof sheds ice onto the meter, tell your gas utility.
- Keep snow off the meterClear by hand, never with a shovel edge.
- Watch roof ice above the meterFalling ice can break a regulator.
- Check vents at furnace and heaterSnow or ice can block exhaust.
- Test CO alarms before the seasonFurnaces and fireplaces raise the risk.
- Know where your gas shutoff isAsk the utility how it should be used.
Seasonal and vacant homes
A cabin or second home may sit unused for weeks. If you smell gas on arrival, do not turn on lights or open the garage with a remote. Walk back out and call from a distance. Before leaving a house for the season, ask your gas supplier or a plumber how to set appliances and shutoffs, and do not light any pilot you are not sure about.
| Situation | Safe move |
|---|---|
| Arrive at a cold house, smell gas | Back out, call from outside |
| Pilot light out after a long absence | Leave it for the plumber if gas can be smelled |
| Space heater plugged into a gas line | Not a DIY job; have a plumber connect it |
| Propane tank with a faint odor | Call your propane supplier from outside |
What happens after a gas leak is found
The utility clears the scene. The repair and the safety checks are a separate step.
Repair and testing
Once the utility or fire department says the building is safe, the line or appliance still has to be repaired. A plumber locates the leak, replaces the failed part, and tests the repaired section before gas is used again. Do not relight any appliance, and do not run a repaired line until it has been tested. If the leak was on an appliance, the appliance may need replacing.
Locate the source
Pressure test and leak finding on the lines.
Replace the failed part
A connector, valve or length of pipe.
Test the repair
Pressure and soap checks before use.
Restore service
Appliances back on, one at a time.
Ways to lower the risk
You cannot see inside a wall, but you can reduce the chance of trouble. Replace old flexible connectors when appliances are moved, call before any digging near a gas line, and have appliances serviced on a regular schedule. Put a gas detector near the furnace and water heater if your home allows it, and place CO alarms outside bedrooms. Read how to shut off the main water valve as well, because emergencies often overlap.
- Replace flex connectorsWhen appliances move or age.
- Mark and call before diggingBuried lines are easy to hit.
- Service furnace and heater yearlyDirty burners and loose parts cause trouble.
- Add detectorsGas alarms low, CO alarms outside sleeping rooms.
- Keep clutter off appliancesEasier to notice a smell and to reach a valve.
When to call a plumber after a gas scare
The utility handles the emergency. A plumber handles the repair once it is safe.
The utility cleared the building but the cause is unknown
A plumber can test the lines and find the leak.
An appliance connector is worn or kinked
Replace it before it fails.
You are adding or moving a gas appliance
Gas piping needs proper sizing and testing.
A faint smell keeps returning
Do not wait. Leave, call from outside, then book a check.
Services after a gas leak
Gas leak repair
Find and fix the source of a leak.
Gas leak repair details →Gas line repair
Repairs to damaged gas piping.
Gas line repair details →Emergency plumber
Open 24/7, same-day service available.
Emergency plumber details →Water heater repair
Gas heater connections and valves.
Water heater repair details →Gas leak questions
What are the signs of a gas leak in your house?
A rotten-egg smell, a hissing sound near a pipe or appliance, dead plants over a buried line, a burner flame that is yellow instead of blue, and headaches or dizziness that ease outdoors. If you notice any, leave first and call from outside.
Should I open windows if I smell gas?
Only if you can do it on your way out without delay. Do not linger to ventilate. Leave the building, move away and call the gas utility or 911 from outside.
Who do I call for a gas leak?
Call your gas utility’s emergency number from outside the building, or 911 if you are unsure or someone feels ill. A plumber comes after the utility clears the building to repair the cause.
Can I use my cell phone inside if I smell gas?
No. A phone is unlikely to ignite gas, but any electrical device carries risk and there is no reason to stay. Walk outside first, then call.
What if the smell goes away?
Do not assume it is fixed. Smell can fade, and a leak may continue. Leave anyway, call the utility and let them check. Book gas leak repair if a cause is found.
Is carbon monoxide the same as a gas leak?
No. Carbon monoxide is a combustion gas with no smell, produced by fuel-burning appliances. Natural gas has an added odor. Both call for leaving the home and calling for help. Keep working CO alarms near bedrooms.
Can I turn off the gas myself?
Do not spend time on it. Leave first. If your gas utility has told you how to use your shutoff, follow that, but never reach for it if it delays your exit.
What causes gas leaks in older homes?
Aging flexible connectors, dried-out valve seals, loose joints, and corroded buried lines are common. Appliance moves and digging damage also cause leaks. Older homes tend to have more connections to wear out.
How much does gas leak repair cost?
It depends on where the leak is, how much pipe or appliance must be replaced, and how hard the line is to reach. A connector swap is a small job; a buried line is larger. Ask about pricing when you call.
Is it safe to relight a pilot after a leak?
Not until the utility or fire department has cleared the home and the repair has been tested. Ask a plumber to relight appliances if you are unsure. We are open 24/7 and same-day service is available.
More safety and plumbing guides
Smell gas? Get out, then call
Leave first and call your gas utility or 911 from outside. For repairs after the all clear, we are open 24/7 with same-day service in Lakeville and nearby towns.