What Should I Do If I Smell Gas or a CO Alarm Sounds?

What should I do when I smell natural gas?

Natural gas is odorless before an odorant gets added. A sulfur or rotten-egg smell can warn that gas may be escaping, and hissing near a gas line or fuel-burning appliance is another red flag. You don't need a second sign before leaving.

Tell everyone to go outside. Help children and anyone who needs assistance, and take pets if you can without delaying your exit. Leave switches and appliances alone. Don't smoke, light a match, use a candle, operate the thermostat, or use a phone inside.

From a safe location, call 911. Then call the Washington Gas Emergency Leak Line at 844-927-4427 and choose option 1. Review Washington Gas gas-leak instructions and wait for emergency personnel or the gas utility.

• Don't try to find the leak or inspect the furnace.
• Don't close a gas valve unless emergency personnel tell you to.
• Don't go back inside to retrieve belongings.

What should I do when a carbon monoxide alarm sounds?

Move everyone to fresh air outside, account for each person, and call 911 from outside. Do this even if nobody feels sick and the furnace still looks like it's working fine. Frederick County Fire and Rescue's CO guidance says to stay outside until the fire department arrives and gives you instructions.

Don't silence the alarm and wait to see whether it sounds again. Don't stay inside while opening windows either. Fresh air may cut exposure after you leave, but ventilation is not a substitute for emergency evaluation.

• Leave even when the furnace looks normal.
• Tell responders which alarm sounded and what equipment was running.
• Don't restart fuel-burning equipment until responders clear it.

Is a gas smell the same as carbon monoxide?

No. A rotten-egg odor is the warning sign for natural gas. Carbon monoxide, or CO, has no smell and no color, so your nose can't catch it at all. The CDC's carbon monoxide guidance explains why CO can cause sudden illness with no sensory warning.

A furnace, water heater, fireplace, vehicle, generator, or another fuel-burning device can all be involved in a CO problem. A gas leak isn't proof that CO is present, and the absence of a gas smell doesn't make a CO alarm safe to ignore.

A suspected gas leak adds an ignition risk, so avoid anything that could spark. A CO alarm means everyone needs fresh air, fast. Skip the DIY furnace troubleshooting.

• Treat both warnings as reasons to leave first.
• Don't judge CO exposure by smell.
• Keep equipment off if responders tell you to.

What symptoms can carbon monoxide cause?

Common symptoms include headache, dizziness, weakness, nausea or vomiting, chest pain, and confusion. Symptoms hitting more than one person in the home, or symptoms that ease up after going outside, are especially concerning. Still, you don't need symptoms to respond to an alarm.

Call 911 for trouble breathing, chest pain, severe confusion, a seizure, loss of consciousness, or difficulty walking. Tell the dispatcher there may have been CO exposure. Don't send a sick person back inside, and don't let them drive.

The CDC lists common CO poisoning symptoms. After reaching fresh air, Maryland residents can also call the Maryland Poison Center at 1-800-222-1222 for exposure guidance. Severe symptoms still belong with 911.

• Account for everyone after leaving.
• Tell 911 about possible CO exposure.
• Don't send a sick person back inside.

Is a chirp the same as a full CO alarm?

Usually not. Alarm sounds vary by brand and model, so learn the pattern printed on your alarm or in its manual. The National Fire Protection Association alarm-sound guide describes 4 repeating loud beeps as a CO warning and a single chirp every 30 or 60 seconds as a possible low-battery signal. End-of-life signals can differ by manufacturer.

If you can't tell whether you heard an alarm or a maintenance chirp, treat it as an alarm. Go outside and call for help. Check the model's instructions only once you're in fresh air. Never replace a battery or unplug an alarm while a suspected gas odor is present.

After the immediate issue clears up, replace a low battery or expired alarm according to the manufacturer's instructions. Test alarms regularly so the sound is familiar before an actual emergency.

• Treat an unclear sound as an alarm.
• Check the manual only after leaving the home.
• Don't unplug the alarm during a suspected gas odor.

When can I go back inside?

Return only when the fire department or gas utility says the property is safe. A quiet alarm, fading odor, or open window isn't clearance. Conditions can change, and neither natural gas nor carbon monoxide can be assessed safely by smell alone.

Follow any instructions about keeping an appliance off. If responders identify a furnace, boiler, water heater, vent, chimney, or other fuel-burning equipment as a possible source, don't restart it until the required inspection and repair are done.

• Wait for emergency personnel or the utility.
• Don't treat a quiet alarm as proof of safety.
• Keep identified equipment off as instructed.

Who should check the HVAC equipment afterward?

Emergency personnel and the gas utility handle the immediate hazard. HVAC service starts after they clear the property. At that point, we can inspect the furnace or other heating equipment, its combustion operation, and connected venting within the service scope. Utility piping or broader house-system problems may need the utility or another qualified trade instead.

For a Frederick County home, HVAC Repair Frederick can take the post-clearance HVAC handoff. Describe what you smelled or heard, which alarms went off, what responders found, and which equipment they told you to leave off. That gives the inspection a clear starting point without making you test the system again.

When you later arrange HVAC gas-leak service, share the responder's instructions. We can inspect equipment after the safety event; it doesn't replace the fire department, gas utility, or emergency responder.

• Get emergency clearance first.
• Keep equipment off if responders instruct you to.
• Share what responders found before the HVAC inspection.