Can You Grill in a Garage With the Door Open? No, and Here Is What the Open Door Actually Does

The rain starts, the burgers are ready, and the garage is right there with the door up. Half the internet says “technically, you can”. At least one site says that on one page and “a resounding no” on another. Pages on this question tend to cite no manual and no measurement. This one has both, and the answer is no.

We have not tested this ourselves, and we are not going to. Everything below comes from the maker documents, the CPSC, and the few published measurements that exist. We say where those measurements stop.

What the open door actually does

Almost nobody has measured this. The one study we found that compared door positions used an ISO shipping container with a double door, not a garage: 33 cubic meters, or about 1,170 cubic feet, which is less than half the volume of the one-car garage in the study below. The researchers burned 1 kilogram of barbecue charcoal (2.2 pounds) with two small fans blowing on it.

Read that honestly, in both directions. An open door made a very large difference, and that is the best evidence the “technically, you can” pages could have, though none of them cites it. But the average hides the peaks. The authors say the half-open and closed runs exceeded UK, EU and WHO guideline values, and that the open-door run’s alarm timing fell within the 15-minute limits but outside the 1-hour limits. Even with the door wide open, the alarms went off in under half an hour, and the half-open door, which is what you get once it starts raining sideways, peaked at more than 800 ppm.

The limits matter. It was one container, smaller than a garage, with one fuel, one run per door position, fans on the charcoal and no wind figures. A bigger space would dilute the gas more; a bigger fire or a grill against the back wall would work the other way. It tells you an open door helps a lot and does not make the space outdoors. It does not tell you what your garage, with your grill, on a still evening, would do. Nobody can.

Closed-garage numbers are much worse. A medical study in a freestanding one-car garage of about 73 cubic meters measured 200 ppm after 20 minutes from a burned-down 2.3 lb bag of charcoal, with levels still rising when the test stopped. That was a study of poisoning methods, not of cooking. German federal researchers modeled 800 grams of charcoal in a typical closed garage at 750 to 1,100 ppm, and measured over 3,000 ppm in a 19 cubic meter chamber. They give the scale: at 200 ppm, slight headaches after two hours; at 800 ppm, dizziness and nausea, and loss of consciousness after about two hours. They also found no significant difference between ceiling height and grill height, because the gas mixes evenly. So the idea that it all rises and leaves through the top of the door is not supported by that work.

We found no published CO measurement for a propane grill, a griddle or a pellet grill in a garage. That is a gap in the data and not a clean result. The CPSC does count deaths involving LP grills and camp stoves, below, without saying where they happened.

What the CPSC says, and what it does not count

The CPSC’s guidance names the place: “Use grills outside only, in well-ventilated areas, and never indoors, in a garage, breezeway, carport, porch or under a surface that will burn.” It said this about ventilation in 1985, and nobody has improved on it: “Opening a window or using a fan will not assure that CO gas will be reduced to safe levels.” That line was about charcoal. Its current page on charcoal is blunter: “Never burn charcoal inside a home, garage, vehicle, or tent.”

The newest CPSC staff report on non-fire carbon monoxide deaths covers 2022 and came out in May 2026:

Those numbers need care, and most pages that quote CPSC figures skip it. The report does not say how many happened in a garage. Most charcoal deaths involved burning it for heat, not cooking. The location table has a line for detached garages and sheds, but it covers every product, and there is no line for grilling in an attached garage. Estimates also get revised in later editions, and the recent years are flagged as incomplete. So do not read this table as “18 people died grilling in garages”. What it does show is that charcoal, grills and camp stoves are linked to carbon monoxide deaths in the US in most years, with the location unknown.

Fire is the smaller story here. NFPA counts 12,141 home grill fires a year for 2020 to 2024. Its last area-of-origin table, for 2014 to 2018, puts about 100 structure fires a year, or 3 percent, in a garage or vehicle storage area. Balconies and patios are far bigger. NFPA counts fires only, so none of that reflects carbon monoxide.

What the makers print

Here are the manuals we read, and whether they use the word.

The sentence that settles “door open”. Blackstone and Weber both print it, in nearly the same words: “All openings must be permanently open; sliding doors, garage doors, windows or screened openings are not considered as permanent openings.” Blackstone then defines outdoors: walls on three sides with no overhead cover; or a roof with no more than two walls; or a roof with three walls as long as at least 30 percent of the perimeter is permanently open. A garage with the door up has a roof, three walls and a door the maker has already told you does not count.

Kamado Joe’s manual explains why, plainly: burning charcoal, wood or propane gives off carbon monoxide, “which has no odor and can cause death”, and poisoning “can easily be mistaken for a cold or flu”.

One manual muddies this. Coyote’s newer C2 document says its grills must not be used in enclosed garages, then says that if you place one in an enclosed space such as a garage, “ensure it is equipped with a properly approved ventilation system.” That describes a commercial-style hood system engineered for the space, and an open door and a box fan are not that.

If you are wondering about a hood fan: rival pages suggest “a ventilation fan” as if it solved this. The CPSC’s sentence above says otherwise, and none of those pages names an airflow.

Three different rules people mix up

The manual and CO. This is what actually stops you. It applies to one- and two-family homes like yours.

The fire code. IFC 308.1.4 says charcoal burners and open-flame cooking devices must stay off combustible balconies and 10 feet from combustible construction. It says nothing about garages or carbon monoxide, and its first exception is one- and two-family dwellings. So a homeowner who says “it’s not against code” may be right about that section, and it still does not answer the question. Apartment and condo rules are stricter, and NFPA 1 states reach further: see fire pits on decks and balconies.

The cylinder rule. This one is about where propane sits. Minnesota’s State Fire Marshal says “cylinders larger than 1 pound must not be stored or used indoors at a residential property”, including in attached and detached garages. So in Minnesota a propane grill running in a garage has a 20-pound cylinder where one is not allowed, regardless of the flame. Other states follow their own adoption of NFPA 58, whose text we could not read. Blackstone agrees: “do NOT store an LPG cylinder inside a building, garage, or any other enclosed area”, and “storage of an appliance indoors is only permissible if the gas supply is disconnected and removed from the appliance.”

Electric does not get a pass

The usual advice is that electric grills and smokers are fine in a garage because they make no fumes. The makers do not agree, and one rival gets the reason wrong in the other direction by saying the element gives off CO. It does not. The answer depends on what you are running.

Electric smokers burn wood. Char-Broil’s electric smoker manual: “Burning wood gives off carbon monoxide which can cause death. DO NOT burn wood chips inside homes, vehicles, tents, garages or any enclosed areas.” Another Char-Broil model lists “a carport, garage, porch, covered patio” as places never to use it. Cuisinart’s COS-330 answers the question in its FAQ: “Can I use the smoker in my garage? No.”

Electric grills and griddles print the ban too. Weber’s Lumin: “Do not use in a garage, building, covered walkway, tent or any other enclosed area or beneath overhead combustible construction.” Blackstone’s electric griddle carries the same outdoor-only garage line, plus “do not expose to rain”. Weber gives no reason. Blackstone’s electric manual even carries the carbon monoxide banner, which looks carried over from its gas manuals, since an electric griddle makes no combustion CO. Either way it is the maker’s rule.

One maker says the opposite. Cookshack’s FAQ says “We recommend using your smoker in your garage or outside on a driveway or patio.” Cookshack’s insulated electric smokers are their own class. If yours is one, check the manual. It does not carry to any other brand.

The catch with rain. Several electric smokers ban both rain and roofs. Masterbuilt says not to expose them to rain, Char-Broil says “Do not cook under a roof”, and that leaves very little room. Plan the cook around the forecast. If you want indoor cooking, NFPA’s line is the clean one: “Only grills intended for indoor use should be used inside.”

A CO detector does not make it safe

One pellet site tells readers a garage is fine with a detector running. Another says to install detectors in the garage. Both miss what the alarm makers say.

• Kidde’s user guide lists it under “Locations To Avoid”: “In the garage.” Starting a car puts combustion products in the air, and garages can fall outside the 40 to 100°F range it wants.
• An alarm reports the gas only at its sensor, and Kidde says its alarms do not prevent CO. “Carbon monoxide gas may be present in other areas.”
• Kidde’s combination alarms “have not been investigated for carbon monoxide detection below 70 PPM.” That leaves room for a long cook to sit under the alarm.
• EPA: “don’t let buying a CO detector lull you into a false sense of security.”
• In the door-position study the alarms warned every time, including at a level far past symptoms in the half-open run. The alarm tells you the gas is already there.

Keep working CO alarms outside the bedrooms and on each level of the house, especially with an attached garage. Residential codes commonly require them. They protect sleepers from a gas that seeps in, and they do not make a burner in the garage acceptable.

The cooldown mistake

Rolling a grill back in while it is warm is the version of this that catches careful people. The container study ran this on purpose, to simulate what it says some poisoning victims do after a barbecue. About 270 grams of leftover charcoal and ash reached 70 ppm in the container.

Let charcoal go stone cold, for as long as your manual says, before it goes anywhere near the garage. Take the cylinder off a gas grill first. Wood pellets deserve a note too: Coyote warns “Wood Pellets can emit Carbon Monoxide while stored in normal conditions. DO NOT store wood pellets in a confined area.” Keep the bags out of small closed rooms.

What to do instead

1. Roll it out to the driveway. That is the whole fix.
2. Give it the manual’s clearance. Kamado Joe says 10 feet from walls, rails and overhead construction. Cuisinart’s smoker says 10 or more feet from any building. recteq’s built-in manual says 60 inches. Weber’s Lumin says 24 inches from combustibles.
3. Shut the door from the garage into the house. Do that whenever anything is running out front.
4. For rain, use a shelter designed to be open. Blackstone’s three-walls rule is a useful test for any shelter. A grill gazebo is open on all sides, but read your own manual first: Kamado Joe bars overhead construction within 10 feet, and Traeger bars combustible overhangs. What each maker says about cover has the exact lines.
5. In the cold, plan for it. See pellet grills in cold, rain and snow.

If someone feels sick

Headache, dizziness, weakness, nausea, vomiting, sleepiness and confusion are the symptoms Kamado Joe’s manual lists, and it warns they get mistaken for flu. If people feel unwell around a grill in an enclosed space, turn it off if you can do that in a few seconds, get everyone into fresh air, and call 911.

Where to next

Picking the grill you will roll outside: pellet grills, flat-top griddles, gas grills, kamados and electric smokers. For a fuel question that comes up in the same cold weather, see how long a 20 lb propane tank lasts.