If You Smell Gas Near Your Water Heater, Here's What To Do

Act First, Diagnose Later

A gas smell near a water heater, furnace, or any gas appliance is treated as an emergency, not a maintenance question. The rotten-egg smell added to natural gas specifically so it's noticeable is there for exactly this reason - your nose is the early warning system, and it's meant to be acted on immediately rather than investigated first.

The sequence below is the same one utilities and fire departments recommend nationally, not something specific to one brand of water heater or one type of home.

What To Do Immediately

Do not operate any light switches, appliances, phones, or anything electrical in the area - a spark from a switch is a real ignition risk in a gas-filled space, however small that risk feels in the moment. Do not light a match or use a lighter to try to locate the source of the smell.

Open doors and windows if you can do so quickly on your way out, to help the gas dissipate, but don't linger to do a thorough job of it. Leave the house and get a safe distance away - the standard guidance is at least a few hundred feet, not just the front yard.

Once you're safely away from the house, call your gas utility's emergency line or 911 from a safe distance, not from inside or right next to the building. Most gas utilities have a dedicated 24/7 emergency number specifically for this, separate from their general customer service line.

What Happens After The Utility Responds

The utility company will typically investigate the source, and if they confirm a leak, they'll shut off gas service to the affected appliance or the whole home until it's safe. That's a separate step from actually repairing whatever caused the leak - a cracked fitting, a failed connection, or an aging component on the water heater itself.

Once the utility has confirmed it's safe and gas service is restored or the specific appliance is isolated, water heater repair addresses the actual mechanical issue that caused the leak in the first place, whether that's a loose or corroded fitting, a failed gas valve, or another component that needs replacement.

Common False Alarms Worth Knowing About

Not every unusual smell near a water heater is a gas leak. A new water heater sometimes has a faint odor from manufacturing residue burning off during its first several uses, which typically clears within a few cycles. A pilot light that's briefly out and being relit can produce a very brief, mild gas smell during normal operation.

That said, when in doubt, treat it as real. The cost of a false alarm - stepping outside for a few minutes while it's checked out - is trivial compared to the risk of assuming a genuine leak is nothing.

After The Immediate Danger Is Addressed

Once the utility or fire department has confirmed the home is safe, the water heater itself still needs a proper inspection before it goes back into regular use. Gas connections, the valve, and any component near where the leak originated should be checked by a plumber familiar with gas appliance connections, not just visually inspected and assumed fine.

If this has happened more than once with the same unit, that's a signal the underlying issue wasn't fully resolved the first time, and it's worth a more thorough assessment rather than repeating the same fix.

Preventing This In The First Place

Gas leaks at a water heater most often trace back to a handful of common causes: a fitting that was never tightened correctly during a prior repair or installation, a flexible gas connector that's aged and cracked, or corrosion at a threaded joint over years of use. None of these are things a homeowner typically notices during normal use, which is part of why a periodic professional check of gas connections, not just the water heater's heating function, is worth including as part of any water heater service visit.

If your water heater is old enough that you can't recall the last time anyone actually checked the gas line and fittings specifically, rather than just the tank and burner, that's a reasonable thing to ask about the next time a plumber is already at your home for any other reason.

Carbon Monoxide Is A Related, Separate Concern

A gas leak and a carbon monoxide issue are different problems that sometimes get confused. Carbon monoxide is produced by incomplete combustion in a gas appliance and is odorless, unlike the deliberately-added smell of a gas leak - which is exactly why a working carbon monoxide detector near sleeping areas matters as a separate layer of protection, not a substitute for recognizing a gas smell. Both warrant the same basic response: leave the area and get help, rather than trying to investigate the cause yourself.