Why Your Charcoal Grill Runs Too Hot or Keeps Going Out

Too hot or not hot enough: the quick answer

Charcoal burns as fast as air can reach it, up to the limit of how much fuel is alight. Almost every temperature problem comes back to one of those two things. Start with the row that matches what your grill is doing.

What is happening	Most likely cause	First thing to try
Runs too hot and will not come down	Bottom vent too open, or too much lit fuel	Close the bottom vent to a quarter and wait fifteen minutes
Not getting hot enough	Not enough lit fuel, or ash blocking the air	Empty the ash, then add a chimney of lit coals
Keeps going out	Vents closed too far, damp charcoal, or coals spread too thin	Open both vents and push the coals together
Loses heat partway through	Fuel running out or ash building up	Add lit coals before the fire fades, not after
Swings up and down	Adjusting the vents too often	Make one small change, then wait fifteen minutes

Close the bottom vent first, and wait fifteen minutes before touching it again.

Why your charcoal grill runs too hot

If it is running hot, the fire is getting more air than it needs, or more of the fuel is alight than the cook calls for. Check the causes below in this order, because the first one is the answer most of the time.

Work through it in this order

Start with the bottom vent, because this is the answer roughly eight times out of ten. Charcoal burns in proportion to the oxygen reaching it. If it is running hot, the vent is more open than it needs to be, or something is holding it open. Close it to a quarter and wait a full fifteen minutes before judging.

Then the fuel load. If you lit a full chimney for a cook that wanted ten lit coals on a bed of unlit, no vent setting will save it. The quantity of lit fuel sets the ceiling; vents only control where you sit under it. Our guide to how much charcoal to use gives the amounts for each kind of cook.

Then wind. Wind forces air through the vents regardless of your setting and can add 28°C (50°F) or more. Move the cooker, turn the bottom vent away from the wind, or build a windbreak.

Then the lid seal. Kettles have no gasket, so if the lid is warped or not seated properly you have an uncontrolled air inlet. Check it sits flush the whole way round. On kamados and drums, check the gasket has not perished.

Then the fire's shape. If your snake ends were touching, or lit coals scattered across the pile when you tipped them in, you have two or three burn fronts instead of one. That will run hot and burn out early, and there is no fixing it mid-cook. The snake method and the Minion method guides show how to lay the fuel so only one part of it burns at a time.

Things that will not fix it

Closing the top vent. This traps stale smoke and makes the food bitter, and it makes the cooker less responsive rather than cooler. Steer with the bottom vent.
Spraying water on the coals. Steam, ash clouds, thermal shock, and on a ceramic cooker a real risk of cracking it.
Opening the lid to let heat out. It briefly drops the air temperature, then floods the coals with oxygen and makes the underlying problem worse.
Adding more meat as a heat sink. It works marginally and for about ten minutes.

The one that catches everyone

Over-correction. You close a vent, nothing happens within two minutes, so you close it further. Fifteen minutes later both adjustments land at once and the fire is dying, so you open everything up, and twenty minutes after that it is at 175°C (350°F). Charcoal cookers have real thermal lag. Make one small change, then wait fifteen minutes before making another.

Why your charcoal grill is not getting hot enough

This is the opposite problem, and it has its own list of causes.

Not enough lit charcoal. Half a chimney will not sear a steak, whatever the vents are doing. For high heat you need a full chimney poured into a deep bed.
The coals were not ready. Charcoal is ready when the top layer is covered in grey ash, around 12 to 15 minutes in a chimney starter. Coals that are still black in places have not reached full heat. See how to light charcoal.
Ash is blocking the air. A thick layer of ash in the bottom of the bowl covers the vent and smothers the coals from below. Empty it before every cook, and sweep the vent blades through a few times during a long one.
The vents are closed too far. Open the bottom vent fully when you want high heat, and keep the top vent open as well.
The coals are spread too thin. Single coals with gaps between them cool each other down. Push them into a deep pile or bank them to one side.
Damp charcoal. Charcoal that has been stored somewhere damp lights slowly and burns cool. Our post on charcoal storage explains how to keep it dry.
Cold weather. In winter the grill loses heat faster and you need more fuel to reach the same temperature. We cover this in charcoal grilling in winter.

A bowl full of ash covers the bottom vent, so the coals above it cannot get enough air to burn hot.

Why does my charcoal keep going out?

A fire that goes out has run short of air or fuel. The most common reason is closing the vents too far, often in an attempt to bring the temperature down. Charcoal needs a steady flow of air through the bottom vent and out of the top one. If either is shut, the fire suffocates, which is exactly how you put a charcoal grill out at the end of a cook.

The other causes are the ones above: ash choking the bottom vent, damp charcoal, and too few coals spread too thinly to keep each other alight. If you light charcoal by pouring lighter fluid over a pile, the flames often burn off before the coals themselves have caught. A chimney starter avoids that, because the coals light each other from below.

To rescue a fire that is dying, open both vents fully, push the remaining coals together, and add a few lit coals from a chimney rather than unlit ones, which will cool the fire further before they catch.

Why does my charcoal grill lose heat during a cook?

A full chimney of briquettes gives about an hour of useful heat, then fades. If a cook runs longer, the fire will drop unless you feed it. Light half a chimney about 15 minutes before you need it and add the lit coals to the fire. Ash building up around the coals has the same effect as a closing vent, so on a long cook, tap or sweep the vent to clear it. Our guide to making a charcoal fire last longer covers topping up in detail.

Opening the lid also costs heat each time. With the lid on, the grill is cooking with hot air as well as the coals. Open it only when you need to turn or move something.

Pit Barrel Cooker running too hot

A drum like the Pit Barrel Cooker is meant to settle on its own at around 135°C (275°F) to 155°C (310°F), with one intake vent set once for your altitude. Below 2,000 feet, which covers all of the UK, the maker says to set it a quarter open.

The maker's own troubleshooting says the usual cause of a Pit Barrel running too hot is the lighting. Too many coals lit in the chimney, or coals left in the chimney too long, sets the whole basket going at once in an empty barrel. Light only the quarter of a basket the instructions call for, tip it in, and hang the meat straight away. After that, check the lid is seated flat, that a thermometer wire is not lifting it, and that you are not opening it more than you need to.

Common questions

Why does my charcoal grill keep going out?

Usually because the vents are closed too far, the bottom vent is blocked by ash, or the coals are spread too thin to keep each other lit. Damp charcoal also burns badly.

Why is my charcoal grill not getting hot enough?

There is not enough lit charcoal, the coals were not fully lit, or ash is blocking the air. Empty the ash, open the bottom vent fully and add a chimney of lit coals.

How do I make my charcoal grill hotter?

Light more charcoal, pour it into a deep pile rather than a thin layer, and open the bottom vent fully. Keep the top vent open as well.

How do I cool down a charcoal grill?

Close the bottom vent to about a quarter and wait fifteen minutes. Move the food to the side with no coals under it while it comes down. Do not spray water on the coals.