Angie's LIST Guide to
Natural gas leaks

Natural gas is the most widely used source of energy for household heating and cooking, and for the most part it's quite safe. However, homeowners need to be vigilant about the risk of natural gas leaks. Every year, people die because of undetected or unrecognized gas leaks. The most common cause of death is asphyxiation, but sometimes a gas-filled basement will explode into a fireball that quickly consumes the entire house.

Though natural gas, or methane, isn’t poisonous, it displaces the levels of oxygen we need to breathe. At sea level, the atmosphere contains 21 percent oxygen, and you need at least an 18 percent concentration to breathe normally. As the methane displaces the oxygen in an enclosed space, you’ll start to get dizzy and disoriented, lose concentration and coordination. As oxygen levels continue to decrease, you’ll feel tired, even exhausted. Your heart rate and breathing will increase. Eventually, you’ll feel nauseated, lose consciousness and stop breathing.

Methane gas is highly combustible, with a small amount producing lots of heat. But it requires just the right mixture with oxygen to cause an explosion in an enclosed space. Less than 5 percent of natural gas in the air isn’t enough to ignite, and more than 15 percent doesn’t have enough oxygen, according to experts interviewed by the Indianapolis Star. So for an average home, at least 10 percent of the gas needs to permeate the air before it can combust.

Also keep in mind that some leaks may start in your basement, which means that if you start to smell gas on the second floor, a large amount may have already accumulated downstairs.

If you suspect your home has a natural gas leak, it’s imperative that you take the following actions:

Leave the area immediately and call your natural gas utility

Finding a gas leak is a serious issue that risks the safety of your home and its occupants. Call the utility company and request they send an inspector or technician to evaluate the problem. It’s better to be safe than sorry and this safety precaution will not result in any kind of cost or fee to the homeowner in most cases.

If the natural gas utility is unavailable or if your home uses natural gas supplied by a tank that’s filled by refill service, call the local fire department. Firefighters are trained and equipped to respond to natural gas leaks.

Do not operate any electrical device or appliance, including cell phones

Operating electrical devices such as light switches, garage doors or electronic devices - even personal electronics - can inadvertently cause a spark or a static electrical charge that can ignite the leaking gas.

Do not smoke, use an open flame, matches or lighters

Again, these could serve as ignition sources for the leaking gas.

Do not try to locate the source of the leak

If a leak is suspected, it’s possible that flammable gas is entering the home and causing a potential fire risk. It’s better to evacuate the area and call an experienced professional rather than trying to find the source of the leak yourself.

Do not try to shut off the supply or gas-fired appliances

Unless you’re a trained gas utility technician, gas-fitting plumber or HVAC technician, in the event of a gas leak, shutting off the gas supply or gas-using appliances should absolutely be avoided. Trying to shut off the gas may cause a spark that could ignite the leaking gas or damage pipes and appliances if done improperly.

Do not start vehicles

A hot exhaust or a spark from a vehicle in the vicinity of a natural gas leak could become an ignition source.

Once the leak has been identified and stopped by the utility company, fire department or another qualified professional, you’ll need to hire a qualified professional to repair the leak. For most pipe-based leaks, a licensed plumber that offers gas supply pipe services will likely be the most qualified professional to make the repairs.

For leaks that originate from home appliances like stoves, call a large appliance repair specialists. And for leaks that originate from heating equipment, a licensed HVAC company will be the best qualified to make repairs.

• Follow the manufacturer’s guidelines when setting the temperature on your gas water heater. The maximum temperature should generally be set at between 110 and 120 degrees to prevent burns or scalding. Use extreme caution when installing a water heater, or call a professional.
• If you use a gas fireplace or gas logs, make sure you keep the chimney damper open. Even with gas fireplaces, make sure your chimney is adequately maintained and free from obstructions. If the fireplace features a key-operated valve, remove the key when the fireplace is not in use.
• If your clothes dryer uses gas, periodically check the lint trap and dryer vent to ensure both are clear from obstructions.
• Ensure a qualified HVAC technician checks your heating system at least once a year. A technician should not only make sure the system is operating properly and efficiently, they should check for proper combustion and venting of exhaust gases such as carbon monoxide.
• Install a carbon monoxide alarm. If not installed or maintained properly, gas appliances can create dangerous build-ups of carbon monoxide, a colorless, odorless and tasteless gas. You can purchase a sarbon monoxide detector for as little as $20. Many municipalities, utilities and fire departments also offer carbon monoxide detectors free of charge.
• Never store flammable liquids such as paint thinners or gasoline near gas appliances.
• Never store combustible materials such as rags, paper or cardboard near gas appliances
• Never attempt to reroute or divert natural gas lines yourself.
• When building new structures on your property such as home additions, sheds, garages or other outbuildings, call 811 before you dig or build to ensure the structure is not built on top of a gas line.
• Follow the manufacturer’s instructions and maintenance guidelines when installing using natural gas appliances. Use only qualified technicians for repairs
• If a flood, earthquake or other catastrophic event damages your home, always check for the odor of gas. If detected, call your local gas utility or fire department.
• Never use natural gas pipes to store clothing or other items on or from. Hanging clothes or other objects from pipes near the ceiling, such as in a basement for example, creates an additional load on the pipe that can create leaks at the joints. Never allow children to hang or swing from natural gas pipes.