Yes — a carbon-monoxide claim that traces back to a flue or heat-exchanger fault after you have finished the job is a completed-operations claim, and the standard general liability form answers it through the products-completed-operations hazard. It is the scenario every HVAC contractor thinks about and few want to name: combustion equipment you installed or serviced lets carbon monoxide reach the occupants, and the bodily-injury claim arrives weeks or months later. This post walks how the coverage responds, why the timing works, and what to confirm on your own policy.
Carbon monoxide is the most serious version of the exposure that defines the trade — the work that fails after you leave. The full general liability treatment lives on the general liability page, and the broader question of whether the policy answers the install that fails after the job is covered in does general liability cover completed operations for HVAC. Here the focus is the carbon-monoxide claim specifically.
Why carbon monoxide is the exposure that defines the fear
A carbon-monoxide loss is the completed-operations claim in its most frightening form. The gas is colorless and odorless, the defect is usually invisible until it is not, and the harm is to people rather than property. A cracked heat exchanger, a misaligned or blocked flue, an improper draft, a venting error on a combustion appliance — any of these can let flue gases reach the living space after the crew has packed up and the invoice is paid.
That is third-party bodily injury arising out of finished work, which is the textbook completed-operations claim. Both a residential service-and-replace shop and a commercial mechanical contractor carry the exposure, because both work on combustion equipment that vents flue gases. What makes carbon monoxide distinct from the other HVAC completed-operations losses — a fire, a failed condensate line — is that the loss is bodily injury to occupants, the most serious thing your finished work can cause.
How completed operations answers the claim
The standard commercial general liability form delivers completed operations through the products-completed-operations hazard: it responds to third-party bodily injury and property damage arising out of your finished work, away from your premises, after the job is done. A carbon-monoxide bodily-injury claim from a combustion-equipment defect lands squarely inside that grant. The coverage is not an add-on you have to invent — on most contractor forms the products-completed-operations hazard is included automatically — but wording and form numbers vary by carrier, so confirm the exact form and edition on your policy and verify the hazard is granted rather than excluded or sub-limited.
A word on the pollution seam, because it comes up. General liability’s pollution exclusion is what removes a refrigerant release from coverage — that is a separate question, addressed by a separate contractor pollution liability line that most HVAC contractors do not carry. A carbon-monoxide bodily-injury claim arising from a faulty combustion install is generally handled on the completed-operations side rather than pushed aside as pollution. Because the exclusion language varies, read the pollution wording and the completed-operations grant together on your own form, and confirm how they interact.
Why the timing works: the occurrence trigger
The frightening thing about carbon monoxide is that the claim can surface long after the work, and the coverage mechanic that matches that is the policy’s trigger. Standard contractor general liability is written on an occurrence basis, which means it responds based on when the bodily injury happened, not when the claim is filed. So a flue or heat-exchanger defect from a job you did under this year’s policy that harms occupants later is generally answered by the policy that was in force when you did the work.
This is the reason an HVAC contractor never lets the general liability policy lapse. The occurrence coverage in force during each combustion job is what answers that job’s later carbon-monoxide claim, and a lapse leaves the most serious exposure in the trade without a policy behind it. If any part of your program is claims-made rather than occurrence, the tail handling — and any extended reporting period — is something to read very closely, because a carbon-monoxide claim is exactly the kind that arrives on a delay.
Where the coverage stops: the ‘your work’ line
Completed operations answers the third-party bodily injury the carbon-monoxide exposure causes — the harm to occupants. It does not pay to tear out and rebuild your own defective heat exchanger or flue work. That cost is addressed separately under the policy’s ‘your work’ exclusion, which is about the work product itself rather than the harm it does to others. The injury to the occupants is the covered side; the rebuild of your own faulty installation is treated differently, and reading the two together before a claim is part of getting the coverage right.
Your own tools and equipment are never a completed-operations matter at all — that first-party exposure runs to contractors equipment. And a refrigerant release sits on the pollution-exclusion seam covered separately in does HVAC insurance cover refrigerant leaks. The carbon-monoxide claim itself is the completed-operations claim; the surrounding exposures live in other parts of the program.
How to check your own policy
The mechanics above turn into three concrete things to confirm — the actionable part of this post:
- Confirm completed operations is granted, not excluded. The products-completed-operations hazard is part of the standard CGL and usually included, but verify it appears on your form rather than assuming it. Wording and form numbers vary by carrier — confirm the exact form and edition on your policy.
- Check the products-completed-operations aggregate. This separate annual limit applies specifically to completed-operations claims. Because a carbon-monoxide claim can be severe, set the aggregate to match your real combustion-equipment volume.
- Confirm the trigger is occurrence, and never let it lapse. The occurrence policy in force during each combustion job is the one that answers its later carbon-monoxide claim, so continuity is part of the coverage.
Manage the exposure on both sides
Carbon monoxide is the exposure where coverage and craftsmanship matter equally. Carry general liability with completed operations confirmed and its aggregate set to your real volume, keep the policy continuous, and treat every combustion job as a claim that could surface later — because it can. A residential HVAC contractor and a commercial HVAC contractor both carry this exposure wherever combustion equipment vents flue gas.
Combustion-analyzer testing, draft and flue verification, heat-exchanger inspection, and documented startup procedures — measured against OSHA safety standards — reduce how often a defect reaches occupants, which is the other half of managing the trade’s most serious exposure. But the coverage question is settled before any of that: a carbon-monoxide claim from finished combustion work is a completed-operations claim. When you are ready, start a quote, read the full general liability treatment, or step back to what drives HVAC insurance costs to see where this coverage sits in the program.