Smell Gas in Your House? What to Do in San Antonio and La Vernia

What the rotten-egg odor tells you

CPS Energy says utilities add mercaptan to colorless, odorless natural gas so a leak smells like rotten eggs, and the Railroad Commission of Texas, which oversees propane safety, says propane is odorized for the same reason.

• Faint still counts. CPS Energy says not to take chances even when the odor is slight.
• Propane settles low. Its vapor is heavier than air and can collect along floors and in ditches.
• Don't blame a low tank. Never assume a propane odor just means the tank is nearly empty.

No switches, phones or garage doors inside

A spark too small to see can ignite gas mixed with room air. CPS Energy's list of things to leave alone on the way out:

• Light switches, on or off. Leave every light as it is.
• Phones, until you're well clear. Carry your cell out or borrow a neighbor's.
• The garage door opener and other appliances. Walk out through a regular door.
• Matches or any flame, even a flashlight switch.

Don't go looking for the source, and leave the thermostat alone too.

Calling 911, CPS Energy or your propane supplier, and what they do

From outside and away from the house, call 911. In San Antonio, also call CPS Energy's emergency line; elsewhere, call the gas company that bills you. On propane, the Commission says to call your supplier, the fire department, or both. Stay out until responders say it's safe.

The utility may shut off or lock the meter, or tag a single appliance, until the problem is fixed; CPS Energy's standards let it refuse gas to unsafe piping. On propane, the supplier's technician takes it from there.

When you need a plumber: repair, pressure test and reconnection

Call us once the house is safe and the leak is on natural gas piping you own: the line from the meter, pipe in the walls or attic, shut-off valves and appliance connectors. We work under Texas plumbing license # M-27587. A fault inside a furnace or other appliance may need that equipment's own technician instead.

1. Locate and repair. The piping goes on a gauge, the leak is traced to the bad valve, connector or pipe, and that part is replaced. See gas line repair.
2. Permit. Inside San Antonio, gas work is permitted through the Development Services Department, and the plumber doing the work pulls the permit. Outside the city, the town or county has its own process.
3. Test and inspection. The system must hold air pressure with no drop, and an inspector checks it where a permit applies. See gas pressure test.
4. Reconnection. In San Antonio, after final approval the City lets CPS Energy know the home is safe to serve; you then call CPS Energy to have the gas turned back on. CPS Energy also offers to light and adjust pilots on water heaters and furnaces.

Faint smells near appliances and around the house

• Range or oven. If the odor lingers after the burner is lit, or you smell gas with every knob off, treat it as a leak.
• Water heater in the garage. The "boiler," as many San Antonio families say, has a flexible connector and gas valve that can loosen. Never relight its pilot while you smell gas.
• Attic furnace or dryer. A bumped or kinked connector can leak a little at a time.
• Outdoors. Hissing or roaring, dead plants, blowing dirt and bubbling water can all mean a leak.
• Hot tap only. A sulfur smell in the hot water, not the air, usually comes from hydrogen sulfide formed in the water heater, often helped along by its magnesium anode rod; see water heater repair. If the cold tap smells as well, the water supply, a softener or the plumbing is the likelier source.

If you can't tell, assume it's gas and step outside.

Carbon monoxide vs gas

A gas leak is fuel with an added odor, and its main risk is fire or explosion. Carbon monoxide comes from burning fuel, and the CDC calls it odorless and colorless. It builds up when a furnace, water heater or range burns or vents poorly, or an engine or generator runs near the house.

• The CDC lists confusion, chest pain, upset stomach or vomiting, headache, dizziness and weakness; someone asleep can die before noticing any of them.
• Keep a battery-powered or battery-backup CO detector near every sleeping area and replace it on the maker's schedule or every five years. A CO-only detector won't sense a gas leak.
• If the alarm goes off, the CDC says to leave right away and call 911.
• CPS Energy says a yellow or orange flame on a gas appliance may mean a problem and should be checked by a qualified technician.

Questions about a gas smell at home

Gas leak repair in La Vernia and San Antonio

Once responders have cleared the house, call (830) 475-2604. For a gas smell we send our on-call plumber right away; repairs that can wait are booked when it suits you. If we make a repair, dispatch costs $0 and first-time customers take $50 off (see the coupons page for terms). Our area includes La Vernia, St. Hedwig, Adkins and China Grove, Floresville, Seguin and east San Antonio; more under gas line services.

Office hours 8 AM–11 PM daily · 24/7 emergency service