Gas and water leaks can have similar warning signs, but they require very different responses. A gas leak can cause a fire, explosion, or unsafe air to breathe, so if you suspect one, leave the house immediately.

A water leak can damage your home, contribute to mold growth, and create electrical hazards. If you are unsure whether you have a gas leak vs. a water leak, put safety first: leave the area and call for professional help.

Gas Leak vs. Water Leak: Key Differences at a Glance

• Gas leak: Leave immediately. Gas can catch fire or explode from a flame or spark. Call for help only after you are safely outside.
• Water leak: Act quickly to prevent property damage. Water can harm walls, floors, furniture, and belongings, and it can be dangerous near electricity.
• If you are unsure: Treat the situation as a gas leak. Leave the area and let trained professionals assess it.

 

Signs of a Gas Leak

Natural gas is odorless, but utilities add an odorant that smells similar to rotten eggs to help people detect a potential leak. A suspected gas leak is an emergency, and homeowners should never investigate or repair it.

Common warning signs include:

• Rotten egg smell: Even a faint sulfur-like or rotten egg odor may indicate a gas leak.
• Hissing or whistling sounds: A hissing, whistling, or roaring sound near a pipe, meter, or appliance may mean gas is escaping.
• Appliance changes: An appliance that will not light, repeatedly goes out, or has an unusual flame may need repair. Do not test the appliance if you suspect a leak.
• Outdoor signs: Blowing dirt, bubbles in standing water, or dead plants may point to a damaged gas line.
• Physical symptoms: Headache, dizziness, nausea, tiredness, or trouble breathing may mean the air is unsafe. Leave immediately and get help.
• Common locations: Gas leaks may occur near gas meters, furnaces, water heaters, stoves, fireplaces, dryers, valves, and gas lines.

What to Do If You Suspect a Gas Leak

If you smell gas or suspect a gas leak, take these steps right away:

• Leave immediately: Get everyone, including pets, outside as quickly as possible.
• Avoid sparks: Do not use lights, phones, appliances, vehicles, matches, lighters, or flames near the suspected leak.
• Do not investigate: Do not move appliances, test pipes, turn valves, or attempt a repair.
• Call from a safe location: Once you are outside and away from the area, call 911 and your natural gas utility.

Minnesota natural gas utilities instruct customers to leave the area immediately and call from a safe location if they smell gas or have a damaged gas line.minnesotaenergyresources+1

Signs of a Water Leak

Water leaks are typically easier to see than gas leaks, although hidden leaks can cause serious damage over time. Watch for these common signs:

• Visible water damage: Puddles, drips, stains, peeling paint, sagging ceilings, warped floors, damp carpet, or wet cabinets.
• Dripping or running water sounds: Water moving inside a wall, ceiling, or floor may indicate a hidden leak.
• Musty odors: A damp or moldy smell can mean water is collecting behind a wall or beneath flooring.
• Water pressure changes: Low water pressure, a toilet that keeps filling, or a pump that keeps running can point to a plumbing leak.
• Higher water bills: An unexplained increase in your water bill may mean water is leaking somewhere in your home.
• Common locations: Check under sinks, behind toilets, near tubs and showers, around water heaters and appliances, at outdoor faucets, and in basements or crawl spaces.

What to Do If You Have a Water Leak

If you find a water leak, act quickly—but only if the area is safe.

• Stop the water: Turn off the nearest shutoff valve or the main water valve, if it is safe to reach.
• Avoid electrical hazards: Stay away from water near outlets, cords, appliances, or your electrical panel.
• Limit damage: Move valuables and catch drips only when it is safe. Stay away from sagging ceilings or damaged walls.
• Check visible pipes and hoses: Look for obvious leaks, but do not take appliances or plumbing equipment apart.
• Dry the affected area: Remove standing water once you’ve addressed electrical and structural hazards. Seek professional help for major damage or mold concerns.
• Call a plumber: A professional plumber can locate the source of the leak and make the necessary repair.

How to Tell Them Apart

The easiest way to tell a gas leak vs. a water leak is to look at the smell, sound, visible damage, and location of the problem.

Warning Sign: Gas Leak vs Water Leak

Smell Often smells like rotten eggs or sulfur May smell damp, musty, or moldy

Sound May hiss, whistle, or roar May drip, spray, or sound like running water

Visible signs May have no visible indoor signs Often causes stains, damp spots, peeling paint, or warped materials

Common locations Near gas meters, appliances, valves, or gas lines Near pipes, toilets, showers, water heaters, appliances, roofs, or foundations

First step Leave immediately and call for emergency help from a safe location Shut off the water if safe and call a professional plumber

If unsure Treat it as a gas leak and leave the area Do not remain inside to investigate

Safety Tip for St. Paul Homeowners

Gas leaks and water leaks require different actions. For a gas leak, leave immediately and call for emergency help. For a water leak, stop the flow if it is safe, avoid electricity, and call a professional plumber.

If you smell gas and also see water damage, treat it as a gas leak first. Leave without touching switches, phones, appliances, or valves, then call 911 and your gas utility from a safe location. Do not return until trained workers tell you it is safe to do so.

FAQs

What should I do if I smell gas in my house?

Leave the house immediately with everyone and all pets. Do not use lights, phones, appliances, matches, or anything that could create a spark; once you are safely away, call 911 and your gas utility.

Can a water leak smell like gas?

Water leaks usually create a damp, musty, or moldy odor rather than a rotten egg smell. If you smell rotten eggs, sulfur, or anything that may be natural gas, treat it as a gas leak and leave immediately.

Is a hissing sound always a gas leak?

Not always. A hissing sound can come from water pressure, air, or appliances, but treat hissing near a gas line, meter, or gas appliance as a possible gas leak until professionals determine otherwise.

Should I turn off my gas if I suspect a gas leak?

No. Do not attempt to turn gas valves on or off if you suspect a leak. Leave the area immediately and let your gas utility or emergency responders handle the situation.

When should I call an emergency plumber in St. Paul?

Call an emergency plumber in St. Paul when a water leak is causing active flooding, threatening electrical equipment, damaging ceilings or walls, or cannot be stopped safely. For a suspected gas leak, leave first and call 911 and the gas utility from a safe location.

Call St. Paul Pipeworks for Water Leak Repairs

For trusted plumbing services in St. Paul and the Twin Cities, contact St Paul Pipeworks. Our local plumbers can help with plumbing emergencies, leaking pipe repairs, water leak detection, and other residential plumbing needs.

If you suspect a gas leak, do not call from inside the home or wait for a plumbing appointment. Leave immediately, call 911, and contact your gas utility from a safe location.