The first chilly nights are here, and for most of us that means the furnace is about to run for the first time since spring. Before you crank it up, take 20 minutes to make sure your heat works and your home is safe.
— Will Barton
Why this one matters
Fuel-burning appliances like gas furnaces, water heaters, and fireplaces can produce carbon monoxide (CO), a colorless, odorless gas. The U.S. Consumer Product Safety Commission (CPSC) warns that heating systems can cause CO poisoning when they’re installed incorrectly, poorly maintained, have blocked or defective venting, or are misused. You can’t see or smell the problem, which is why an inspection and working alarms both matter.
Get the annual inspection
The CPSC recommends having a professional inspect all fuel-burning heating equipment every year: furnaces, boilers, fireplaces, wood stoves, water heaters, chimneys, flues, and vents. A good inspection checks that vents and flues aren’t leaking, blocked, loose, or disconnected.
Book it now. HVAC companies get busy once the first real cold snap hits, and it’s better to find a problem on a mild October day than on a January night.
Check your alarms
Here’s where the CPSC says alarms belong:
Carbon monoxide alarms on every level of the home and outside sleeping areas
Smoke alarms on every level of the home and inside each bedroom
Press the test button on each one. Replace the batteries if you can’t remember the last time you did, and check the date on the back. Alarms don’t last forever, so follow the replacement schedule printed on yours.
If a CO alarm goes off, don’t go looking for the source. Get everyone outside to fresh air and call 911.
Do-it-yourself furnace basics
Replace the furnace filter. A clogged filter makes the system work harder.
Clear the area around the furnace and water heater. Boxes, laundry, and paint cans don’t belong there.
Make sure the vents and return grilles in each room aren’t covered by furniture or rugs.
Run the heat on a mild day to test it. A light dusty smell the first time is common. A smell that doesn’t go away is a reason to call a professional.
If you ever smell gas, leave the house first, then call 911 or your gas utility from outside.
Space heaters and generators
Turn off space heaters when you go to sleep.
Never run a generator indoors or in a garage. The CPSC says to place portable generators at least 20 feet from the house, with the exhaust pointed away from any building.
Your checklist this week
Schedule a furnace and water heater inspection.
Test every smoke and CO alarm, and add any that are missing.
Swap the furnace filter.
Clear the space around the furnace and water heater.
Have the chimney and flue inspected if you plan to use the fireplace.
Next week: how to keep your pipes from freezing this winter.
— Will Barton
Sources
CPSC, Keep Warm and Safe This Winter (2026): https://cpsc.gov/Newsroom/News-Releases/2026/Keep-Warm-and-Safe-This-Winter-Tips-for-Using-Generators-Furnaces-and-Space-Heaters
CPSC, annual furnace inspection and CO alarm guidance: https://www.cpsc.gov/Newsroom/News-Releases/2005/Install-a-carbon-monoxide-alarm-in-your-homeCPSC-Urges-Annual-Furnace-Inspection-to-Prevent-CO-Deaths
CPSC and CDC, winter home heating hazards: https://www.cpsc.gov/Newsroom/News-Releases/2007/CPSC-and-CDC-Warn-of-Winter-Home-Heating-Hazards-and-Remind-Consumers-to-Replace-Smoke-and-CO-Alarm-Batteries