Quick Summary
- Fairfax County Fire and Rescue says heating equipment failures and malfunctions are one of the leading causes of home fires.
- The county recommends a professional cleaning and check of your heating system every year, ideally in the fall.
- Carbon monoxide alarms should be on every level of the home and outside sleeping areas, and should be tested at least monthly.
- Fairfax County has a limited supply of free CO alarms for residents who need one, installed by a local fire station.
- Daylight saving time ended Sunday, November 1, 2026, so now is a good time to test your alarms if you have not already.
In this post: The first cold night | Start with the furnace | Fireplaces and space heaters | The alarm that has no smell | If you are buying or selling | Sources and reporting limits | FAQ
The First Cold Night Is a Bad Time to Find Out
Most of us don’t think about the furnace until the first morning the house feels chilly. Then the system kicks on after seven months of sitting idle, there’s that dusty burning smell for a few minutes, and we hope for the best.
That hope is exactly what Fairfax County Fire and Rescue would like homeowners to replace with a short checklist. The department’s heating safety page states that heating equipment failures or malfunctions are one of the leading causes of home fires. It’s a plain, unglamorous warning, and it’s the sort of thing that gets easy to ignore when the weather is still mild in late October.
3 feet The minimum clearance Fairfax County Fire and Rescue recommends between combustibles and your furnace, hot water heater, wood-burning device, or space heater.
Start With the Furnace and the Water Heater
The county’s guidance is simple: have a professional clean and check the heating system each year. Its page says that can help prevent fires and improve energy efficiency, which is a nice two-for-one. The county’s carbon monoxide material adds that gas furnaces and other fuel-burning appliances should be inspected by a qualified technician every fall.
Then there’s the stuff you can do yourself in ten minutes. Walk the basement or utility closet and look at what is sitting near the furnace and water heater. Paper, clothing, trash, and storage boxes tend to creep closer over time. The county’s advice is to keep combustibles at least three feet away. If your utility room doubles as a storage room, as it does in a lot of Northern Virginia townhomes where space is tight, this is the single easiest fix on the list.
Fireplaces and Space Heaters Need Their Own Attention
If you burn wood, the county recommends a licensed chimney sweep inspect the chimney at least once a year. It also suggests a glass or metal spark screen in front of the fireplace, caps on chimneys, and storing hot ashes in a covered metal container outside, well away from the house. Never use gasoline, kerosene, or lighter fluid to start or revive a fire.
Space heaters get a few rules of their own. Keep them away from curtains, beds, clothing, and children, and turn them off when you leave the room or go to bed. Never refuel one while it is running or still hot. Look for one with an automatic shut-off in case it tips over. The Virginia Department of Health echoed a similar message in a January 25, 2026 statement from Governor Abigail Spanberger: don’t leave space heaters running while sleeping or unattended, and plug them straight into a wall outlet rather than a power strip.
The Alarm That Goes With a Gas Furnace
Carbon monoxide is colorless, odorless, and tasteless, according to a Fairfax County Fire and Rescue fact sheet. That’s why a working alarm matters more than your nose. The county lists common sources: defective gas or oil furnaces and water heaters, cracked chimney flues, charcoal grills used indoors, a gas oven or range used to warm a room, a car left running in an attached garage, and a fireplace damper closed before the fire is fully out.
On placement, the county’s guidance is to install alarms outside each sleeping area and on every level of the home, following the manufacturer’s instructions, and to test them at least monthly. Look for a UL label. The county’s CO alarm program page puts the price at roughly $35 to $50 at many local hardware stores and says plug-in models last about 10 years. A CO alarm does not detect smoke, so you still need smoke alarms on every level too.
About 10 years The typical life of a plug-in CO alarm, according to Fairfax County’s alarm program page. Check the date printed on the back of yours.
If an alarm sounds, the county says to get everyone outside into fresh air right away and call 911 from a safe spot. Do not stop to open windows. Firefighters will take readings to find the source.
If cost is the obstacle, the county says it has a limited number of free carbon monoxide alarms for residents who need one, and a local fire and rescue station will come to your home and install it. The listed contact is the Public Affairs and Life Safety Education section at 703-246-3801.
Daylight saving time ended on Sunday, November 1, 2026, so if you did not test your alarms when the clocks changed, now is a good time to press the test button on every alarm in the house.
If You Are Buying or Selling This Winter
Heating season is also the season when a lot of Northern Virginia homes change hands, and furnace age and condition come up in nearly every inspection. If you’re a buyer touring in Reston, McLean, or Burke, it’s reasonable to ask when the furnace and water heater were last serviced and to note where the alarms are. You can read more about how I work with buyers on my Reston and McLean pages.
If you’re selling, a recent service receipt and fresh alarm batteries are small things that make a house feel cared for. They cost very little and they answer a question buyers are already thinking about.
Sources and Reporting Limits
- Fairfax County Fire and Rescue, “Heating systems safety” page (fairfaxcounty.gov/fire-ems/heating-systems-safety). The page shows a last-modified date of November 17, 2017, so confirm current guidance with the department.
- Fairfax County Fire and Rescue, “Carbon monoxide alarm program” page (fairfaxcounty.gov/fire-ems/carbon-monoxide-alarm-program). Also shows a 2017 modification date. Alarm prices and availability may have changed, and the program is described as limited with no stated end date.
- Fairfax County Fire and Rescue, carbon monoxide alarm fact sheet (PDF), retrieved October 21, 2026.
- Virginia Department of Health blog, statement from Governor Abigail Spanberger, January 25, 2026, on carbon monoxide and cold-weather safety.
Limits: Two county documents give different annual figures for accidental home carbon monoxide deaths, so this post doesn’t cite a death count. This post is general information and not a substitute for an inspection by a licensed technician. For emergencies, including gas leaks, call 911.
FAQ
How often should a furnace be serviced?
Fairfax County Fire and Rescue recommends a professional cleaning and check every year, and suggests fall for gas and oil appliances.
Where should carbon monoxide alarms go?
The county says outside each sleeping area and on every level of the home, installed according to the manufacturer’s instructions.
I can’t afford an alarm. Is there help?
Fairfax County says it has a limited number of free CO alarms for residents who need one. Call 703-246-3801 and a local fire station will install it. Availability may change, so ask when you call.
What do I do if my alarm goes off?
Leave the house immediately, then call 911 from a neighbor’s home or other safe location. The county advises against stopping to open windows.
If you’re thinking about a move this winter and want a local read on the market, reach out to me anytime.