How long do smoke alarms, CO alarms and fire extinguishers last?
These three are the exception on this site. Everywhere else a service life is a figure read out of trade literature and baseline charts; here the makers and the fire-code people publish a replace-by age themselves, print it on the label, and in the case of the alarms build it into the device so it tells you out loud when it is done. The numbers below are theirs, stated as they state them, with the warranty term beside each one.
Updated
Every material on one 30-year axis
Soft band: typical service-life range. Solid bar: the published warranty term. The difference between their right-hand ends is the story.
The numbers, with their sources
| Material | Service life | Warranty term | Source tier |
|---|---|---|---|
| Smoke alarm | 8–10 yrs | 10-year limited, conditional | Tier 2 · trade / standards literature |
| Carbon monoxide alarm | 7–10 yrs | 10-year limited, non-transferable, conditional | Tier 1 · manufacturer document |
| Fire extinguisher | 12+ yrs | 6-year limited, conditional | Tier 1 · manufacturer document |
Read the two bars against each other and one pattern runs through all three. On the alarms, the warranty term and the service life are the same number — ten years — and that looks like a matched pair until you notice they are promises about different things: one is a remedy if a new alarm turns out to be defective, the other is the sensor switching itself off on schedule, which no warranty treats as a fault. On the extinguisher the two bars come apart hard: Amerex's paper covers six years, while NFPA 10's cycle carries the device to twelve and, for a rechargeable cylinder that keeps passing its test, past that. The alarms are the only things in a house that announce their own end of life. The extinguisher does not — its gauge is the whole conversation, and it only speaks if someone looks.