A heat exchanger doesn’t look like a safety device. It’s a hidden metal component inside a furnace that most business owners never see and never think about, right up until it fails. When it does, the risk isn’t a cold building. It’s carbon monoxide.

What Carbon Monoxide Does to the Body

Carbon monoxide is a gas produced whenever fuel burns, and a properly working heating system vents it safely outside. It has no color and no smell, which means people exposed to it usually have no idea anything is wrong until symptoms show up. Low-level exposure often looks like a headache, dizziness, fatigue, or nausea, symptoms that get mistaken for a flu or just feeling run down. Higher levels of exposure cause confusion, loss of coordination, and can become fatal, particularly for anyone exposed for an extended period in an enclosed space.

For a business, this risk isn’t limited to one person. Employees working a full shift and customers seated for an hour or two are both breathing the same air, in the same building, for extended stretches of time. A slow leak that a single homeowner might notice as “the house feels stuffy” can affect dozens of people in a commercial space before anyone connects the dots.

How a Heat Exchanger Actually Fails

A heat exchanger separates the flame and combustion gases inside a furnace from the air that gets warmed and circulated through the building. It’s made of metal that heats up every time the furnace runs and cools back down every time it shuts off, cycle after cycle, season after season. Over years of that expansion and contraction, along with normal corrosion, the metal can develop small cracks. Most heat exchangers are only rated to last a certain number of years before this kind of fatigue becomes a real risk, and a crack that starts small doesn’t stay that way. Once it’s there, it’s a direct path for carbon monoxide to enter the air stream instead of getting vented outside.

Why a Quick Look Isn’t Enough

Cracks in a heat exchanger are often hard to see, especially early on, and they’re located inside the furnace where a casual glance isn’t going to catch much. Technicians use a few specific methods to actually confirm whether a heat exchanger is compromised:

• Borescope camera inspection. A small camera is used to look inside the heat exchanger for cracks, corrosion, or separation that isn’t visible from outside the unit.
• Carbon monoxide testing under load. Readings are taken while the system is actually running, since a crack can behave differently under heat and pressure than it does when the system is off.
• Flame observation. A flickering or yellow flame, instead of a steady blue one, can indicate a combustion problem that’s sometimes tied to heat exchanger issues.
• Pressure or dye testing. In some cases, technicians use additional testing methods to confirm a suspected crack that isn’t clearly visible even with a camera.

This is why a heat exchanger condition isn’t something a business owner can reliably judge on their own, and why “it seems fine” isn’t the same as “it’s been tested.”

A Business Owner’s Responsibility

Beyond the mechanical side of it, there’s a liability question business owners don’t always think about until something goes wrong. If employees or customers are exposed to carbon monoxide because of equipment that was never tested, that’s a health and safety issue that extends well past the cost of a repair. Many jurisdictions require carbon monoxide detectors in commercial buildings with fuel-burning appliances, and even where it’s not strictly required, having working detectors and a tested heating system is a basic part of keeping a building safe for the people in it.

What to Do If You Suspect a Problem Right Now

If a carbon monoxide detector is alarming, or if staff are reporting symptoms like unexplained headaches, dizziness, or nausea that seem to improve when they leave the building, treat it as urgent. Get everyone out, shut down the heating system if it’s safe to do so, ventilate the space, and contact a qualified technician before running the system again. This isn’t something to wait on until a convenient time.

Getting Ahead of It

The good news is that a cracked heat exchanger is entirely preventable from becoming a crisis. Regular inspection catches the problem while it’s still a repair, not an emergency. Rice Equipment tests heat exchangers and carbon monoxide levels as part of our commercial HVAC service for Springfield businesses. Visit our HVAC services page to learn more, or contact us to get your system checked.

FAQs

What is carbon monoxide and why is it dangerous? Carbon monoxide is a colorless, odorless gas produced by burning fuel. It’s dangerous because it can be inhaled without any warning signs, and exposure ranges from headaches and dizziness at lower levels to confusion and life-threatening effects at higher levels or with prolonged exposure.

What are the symptoms of carbon monoxide exposure? Common symptoms include headache, dizziness, fatigue, and nausea, which are often mistaken for the flu or general tiredness. Symptoms that improve after leaving a building and return after coming back are a warning sign worth taking seriously.

How do technicians actually test for a cracked heat exchanger? Technicians typically use a borescope camera to visually inspect inside the heat exchanger, test carbon monoxide levels while the system is running, observe flame color and behavior, and in some cases use additional testing methods to confirm a suspected crack.

Should my business have carbon monoxide detectors installed? Yes. Many jurisdictions require carbon monoxide detectors in commercial buildings with fuel-burning appliances, and having working detectors is a basic safety measure regardless of local requirements.

What should I do if I suspect a carbon monoxide problem right now? Treat it as urgent. Evacuate the affected area, shut down the heating system if it’s safe to do so, ventilate the space, and contact a qualified technician before running the system again.