Gas Furnace Safety: What Homeowners Need to Know

New Mexico homeowners can ensure gas furnace safety by keeping the area around the unit clear, replacing dirty air filters monthly, and installing carbon monoxide detectors on every floor. Schedule an annual professional furnace inspection, especially if you notice yellow flames, gas odors, or frequent system shutdowns. 

If you smell gas or hear a hissing sound, evacuate the home immediately and call the New Mexico Gas Company at 888-664-2726. Built-in safety components like flame sensors and limit switches help prevent fires and gas leaks, but they don’t replace proper maintenance.

In this guide, you will learn how to identify common gas furnace safety risks, recognize warning signs of unsafe operation, and understand the role of maintenance and safety features in preventing hazards. 

If you have concerns about your gas furnace or want a professional safety inspection, contact Air Control Services in Las Cruces, NM, at (575) 636-2754.

Here are some basic safety practices to protect your home during the heating season.

• Keep flammable materials away from the furnace area
• Replace air filters regularly to support proper airflow
• Keep supply and return vents clear at all times
• Never block exhaust or intake vent pipes
• Check the pilot light or burner flame for proper color
• Install carbon monoxide detectors on every level of the home
• Listen for unusual noises during furnace operation
• Do not ignore repeated shutdowns or error codes
• Avoid DIY repairs involving gas lines or internal components
• Schedule professional safety inspections annually

Carbon monoxide detectors alert homeowners to dangerous CO levels before symptoms appear. Carbon monoxide is colorless and odorless, which is why it builds up without warning. This can lead to headaches, dizziness, nausea, confusion, loss of consciousness, and can become life-threatening with prolonged exposure.

Installing a safety device, such as a carbon monoxide detector, helps New Mexico homeowners respond quickly and safely.

We recommend the following CO alarm placement in New Mexico:

• Outside sleeping areas
• On every level of the home
• Near the furnace, but not directly next to it
• Away from bathrooms, kitchens, and direct airflow vents

Proper maintenance is necessary to keep your CO detector reliable when it is needed most.

• Testing alarms monthly to confirm they are working
• Replacing batteries as needed or when alerts sound
• Replacing detectors according to manufacturer guidelines
• Keeping alarms free of dust and debris
• Never disabling or ignoring an active alarm
• Leaving the home immediately and seeking fresh air if an alarm sounds

If your carbon monoxide detector alarms or you have concerns, contact Air Control Services at (575) 636-2754.

If you think your furnace has a gas leak:

• Leave the home right away: If you smell gas or hear a hissing sound, get everyone outside immediately, including pets.
• Do not use electronics: Avoid turning lights on or off, using phones, or plugging in devices while inside the home.
• Do not attempt to fix the problem: Never try to locate or repair a leak yourself. Call furnace repair professionals.
• Call your gas utility from a safe location: Once outside and away from the home, contact the New Mexico Gas Company at 1-888-664-2726 to report the suspected leak. They can shut off service and inspect the gas line.
• Ventilate only if it is safe: If the odor is faint and you can do so safely, open doors or windows as you exit to allow the gas to escape.
• Contact a licensed HVAC professional: After the utility confirms the area is safe, schedule a professional inspection to identify and correct the source of the issue.

Gas furnace maintenance and safety inspections should be scheduled once a year, ideally before the heating season begins. Homeowners should also schedule an inspection if the furnace displays warning signs, such as unusual odors, frequent shutdowns, unusual noises, or changes in flame color.

An inspection is also recommended after a carbon monoxide alarm, a suspected gas leak, or if the furnace has not been serviced in over a year.

If you notice any of the following issues, your gas furnace may be operating unsafely.

• Unusual gas or burning smells
• Yellow or flickering pilot light
• Banging, rattling, or squealing noises
• Frequent shutdowns or short cycling
• Soot buildup around the furnace or vent pipes
• Visible corrosion on components
• Headaches, dizziness, or nausea while indoors

Gas furnaces can develop safety issues when components fail, airflow is restricted, or maintenance is delayed. Below are some of the most common risks homeowners in Las Cruces, NM, should be aware of:

• Gas leaks: Loose fittings, damaged utility lines, or aging connections can allow natural gas to escape, increasing the risk of fire or explosion.
• Carbon monoxide leaks: Cracked heat exchangers, blocked exhaust vents, or incomplete combustion can release carbon monoxide into the home. This causes headaches, dizziness, nausea, or serious health issues with prolonged exposure.
• Blocked or damaged venting: Debris, snow, or corrosion in vent pipes can prevent exhaust gases from exiting the home properly.
• Overheating: Dirty air filters, blower problems, or restricted airflow can cause the furnace to overheat and shut down or damage internal components.
• Electrical and control failures: Faulty wiring, worn sensors, or failing safety switches may prevent the furnace from shutting off during unsafe conditions.

Built-in safety features in furnaces work together to monitor flames, temperature, airflow, and gas flow. They automatically shut the system down when unsafe conditions are detected to reduce the risk of fire, gas leaks, and carbon monoxide exposure.

The thermocouple senses heat from the pilot light in older furnaces. If the pilot flame goes out, the thermocouple signals the gas valve to close. This prevents unburned gas from flowing into the furnace.

The limit switch monitors the furnace’s internal temperature. If the system overheats due to restricted airflow, dirty filters, or mechanical failure, the switch shuts the furnace down to reduce fire risk and component damage.

If you have concerns about gas furnace safety or want to schedule a professional inspection, contact Air Control Services in Las Cruces, NM, at (575) 636-2754 to get expert help.

Venting and backdraft risks occur when combustion gases cannot exit the home properly and flow back indoors. This is often due to blocked vents or improper combustion air flow, which can spread harmful fuel byproducts.