Inspection · Boise, ID · Firefighter-Owned
Carbon Monoxide Testing and Prevention
CO is odorless and invisible. As firefighters, we respond to CO emergencies regularly. Let us test your chimney system and venting to make sure your home is safe.
Why it matters
Carbon monoxide is colorless, odorless, and produces symptoms that are easy to attribute to something else. Headaches, fatigue, and nausea are the early signs of CO exposure, and they are also the symptoms of the flu, a poor night's sleep, and dozens of other common conditions. By the time CO exposure is severe enough to be unmistakable, it is an emergency. At A Fireman's Chimney Sweep, our team has responded to CO calls in Boise and surrounding areas as active firefighters. We carry professional-grade CO detectors and include systematic venting checks in every chimney service we perform.
Credentials
Firefighter-Owned
Active and former firefighters
NFI Certified
National Fireplace Institute
BBB A+
Better Business Bureau
Licensed & Bonded
State of Idaho
Fully Insured
General liability + workers comp
01
How Chimneys Cause CO Exposure
Combustion produces carbon monoxide as a byproduct. In a functioning chimney system, draft pulls those gases up and out of the home before they can accumulate. When draft fails, the gases follow the path of least resistance instead, which is often back into the living space. Blocked flues are the most obvious cause: bird nests, debris, and animal carcasses in the flue can reduce or stop draft entirely. Cracked liners create secondary paths where CO leaks out before reaching the flue exit. Negative pressure from kitchen and bathroom exhaust fans, dryer operation, or tight modern construction can overcome draft and pull flue gases into the home. Each of these conditions can exist in a chimney that otherwise appears to be functioning normally.
02
Why Firefighters Take CO Seriously
Our team has responded to CO emergencies. We know what a CO call looks like: a family with headaches that got worse after running the furnace all day, or a person who felt fine in the morning and needed hospitalization by the afternoon. Residential CO poisoning is underreported because CO symptoms are frequently misidentified. People take aspirin and go to bed. Detectors with low batteries or end-of-life sensors do not alarm. We approach CO safety testing with the same methodical attention we bring to chimney fires, because the consequences of missing it are comparable.
03
Limitations of Residential CO Detectors
UL-listed residential CO detectors are calibrated to alarm at sustained concentrations above a threshold, not at any detectable CO level. A detector that does not alarm is not confirmation that CO is absent. It is confirmation that CO has not reached the alarm threshold for the required duration. Slow CO leaks from minor chimney problems can produce sub-threshold exposure over hours without triggering an alarm. In homes where residents have adapted to minor symptoms or where the firebox is used infrequently, the problem may go undetected for seasons. Our calibrated instruments measure actual CO concentrations in real time, at the source and in the living space, under operating conditions.
04
What We Test During a CO Safety Service
We test CO concentrations at the appliance, inside the flue, and in the surrounding living space while the appliance is operating. We measure draft performance under operating conditions, not just at rest, because some backdrafting conditions only occur during simultaneous operation of the appliance and other exhaust sources in the home. We inspect the flue liner for cracks or gaps using camera equipment where the flue is accessible. We verify that gas appliances venting through the chimney are properly connected and that connector sizing matches the appliance specifications. Every test result is documented.
05
CO Safety for Gas Appliances and Furnaces
Wood-burning fireplaces are not the only CO source in a chimney system. Gas furnaces, water heaters, and gas fireplace inserts all vent combustion gases through flues that require the same inspection standards as a wood-burning chimney. High-efficiency furnaces are especially prone to venting problems because their lower exhaust temperatures cause condensation in oversized flues, accelerating liner deterioration. Annual inspection of all fuel-burning appliance venting is the same recommendation for gas equipment as it is for wood-burning equipment. We test and inspect all fuel types.
Schedule service
CO exposure does not give you a warning before it becomes serious. Call (208) 890-4588 to schedule a CO safety inspection.
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