What Is a CO Shut-Off Generator, and Is It Worth It?
By the Generator Size Calculator Team · Updated · 5 min read
Quick answer: A CO shut-off generator has a sensor that turns the engine off when carbon monoxide builds up near the unit. The CPSC says to look for one, and estimates that models certified to PGMA G300-2018 would reduce CO poisoning deaths by 87% and models certified to UL 2201 by 100%. It is a safety net, not a license to run the generator near the house.
What a CO shut-off does
Many newer portable generators include a carbon monoxide sensor. If the sensor detects a dangerous level of CO near the generator, it shuts the engine off automatically. This protects people who run a generator in a place where gas can collect, or who do not notice a problem in time. It is the generator equivalent of a smoke alarm that also cuts the fire.
What the CPSC estimates
| Certification | Estimated reduction in CO poisoning deaths |
|---|---|
| PGMA G300-2018 | 87% |
| UL 2201 | 100% |
These are CPSC estimates, based on its analysis of past deaths, for generators certified to those standards. They show how much a good design can matter. They are not a guarantee for any single generator. The CPSC says to look for a generator with a CO shut-off feature.
What to check when buying
- Look for the certification on the box or spec sheet: PGMA G300-2018 or UL 2201.
- Read the manual to learn how the shut-off works and what its indicator light means.
- Compare with other features you need, such as watts and noise. See inverter vs conventional generators and the portable generator calculator.
What a shut-off cannot do
A shut-off is not a reason to move the generator closer. The CPSC still says to run it outside, at least 20 feet from the home, and to install CO alarms on every level. A shut-off can fail or be bypassed, and it does nothing for a generator you already own without one. Read can you run a generator in a garage and how far a generator should be from your house.
Add up your loads before you shop.
A CO shut-off does not make it safe to run a generator indoors. Carbon monoxide has no smell or color. If a carbon monoxide alarm sounds, or anyone feels dizzy, has a headache or feels sick while a generator is running, get to fresh air and call 911. See how far a generator should be from your house.
Frequently asked questions
What is a CO shut-off on a generator?
A sensor that turns the engine off automatically when carbon monoxide builds up near the generator.
Do all generators have CO shut-off?
No. Many newer models do. The CPSC says to look for the feature, so check the spec sheet.
What is PGMA G300-2018?
A safety standard for portable generators. The CPSC estimates that models certified to it would reduce CO poisoning deaths by 87%.
What is UL 2201?
A safety standard for portable engine-generator assemblies. The CPSC estimates that models certified to it would reduce CO poisoning deaths by 100%.
Can I run a CO shut-off generator in the garage?
No. The CPSC still says to run any portable generator outdoors, at least 20 feet from the home.
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Sources: U.S. Consumer Product Safety Commission, portable generator safety and carbon monoxide statistics (look for a CO shut-off; PGMA G300-2018 and UL 2201 certified models estimated to reduce CO poisoning deaths by 87% and 100%).