Carbon Monoxide and Your Air System: What Every Homeowner Should Know

First, our lane, stated plainly: we clean air ducts and dryer vents — we do not service furnaces, water heaters, or any combustion appliance. Carbon monoxide prevention belongs to your HVAC professional, your gas utility, and your alarms. But nearly every duct customer with gas appliances shares a home with CO sources, and the air system we work on is the machinery that moves air through that home. So here are the basics we think every homeowner should know cold — and exactly who to call for what.

Where CO comes from

Carbon monoxide is the colorless, odorless product of incomplete combustion. In a home, that means fuel-burning equipment: gas furnaces and water heaters, gas ranges, gas clothes dryers, fireplaces and wood stoves, portable generators, and vehicles idling in attached garages. Properly installed, vented, and maintained appliances shed their combustion byproducts outdoors. CO problems are almost always a venting problem, a maintenance problem, or a misuse problem (the CPSC's CO center catalogs all three).

How the air system fits in

• Ductwork spreads whatever it's given. Ducts don't create CO, but a system that recirculates a home's air several times an hour will distribute CO from a leaking source to every room — including bedrooms. That's a reason for alarm placement on every level, not a reason to fear your ducts.
• The gas dryer is the overlap case. A gas dryer's exhaust vent carries combustion byproducts out with the lint and moisture. A lint-blocked vent on a gas dryer doesn't just raise fire risk — it can push CO back into the laundry room. This is the one CO pathway our dryer vent cleaning directly removes.
• Starved airflow stresses the furnace. A furnace running chronically hot against a clogged filter lives on its safety limits, and long-term heat stress is hard on the heat exchanger — the wall between your combustion gases and your breathing air. Filter discipline is equipment protection with a CO dividend.

Alarms: the non-negotiable layer

The CDC's prevention guidance is unambiguous: battery-operated or battery-backup CO alarms on every level of the home and near sleeping areas, checked twice a year (the clock-change weekends are the classic anchor), replaced per the manufacturer's schedule — typically every 5–7 years. If your home has any fuel-burning appliance or an attached garage and no CO alarms, that's the single most important item on this page.

Symptoms worth knowing

Low-level CO exposure mimics the flu without the fever: headache, dizziness, fatigue, nausea. The tell is the pattern — symptoms that improve when you leave the house and return when you do, or multiple household members (pets included) sick at once. If that pattern ever fits, get out, then get it investigated.

Prevention that actually works

1. Annual professional service for every fuel-burning appliance — a licensed HVAC technician, not us.
2. CO alarms per CDC guidance, tested twice a year.
3. Never run generators, grills, or vehicles in enclosed or attached spaces.
4. Keep venting clear — appliance flues intact, and the gas dryer's exhaust cleaned annually.
5. Act on red flags — soot around an appliance, a pilot flame that's yellow instead of blue, moisture on windows near an appliance. Our guide to urgent air-system red flags covers what can't wait.