Carbon monoxide — read this first
Stop and deal with this first
Never move a cooker indoors, into a tent, a garage or a porch to control its temperature or to get out of the weather. A solid-fuel cooker keeps producing carbon monoxide as it cools, so 'the fire is nearly out' is not a safe state to bring one inside.
The smoker is running too hot
Chamber temperature has climbed above the target band and closing things down is not bringing it back quickly.
Work out which one it is
Each cause below lists the signs that point at it rather than at the others. Start with the signs, not with the fix.
The intake is admitting more air than the target temperature needs.
commonSigns it is this one
- The temperature is still climbing rather than sitting steady.
- The intake vent is more than slightly open.
Why it happens: On a solid-fuel cooker, temperature is controlled by air rather than by fuel: the fuel is already there and the intake decides how fast it burns. An intake open wider than the cook needs produces a fire that keeps accelerating.
What to do
- Close the intake down in small increments and wait several minutes between each. — during cook, reliable
Solid-fuel cookers respond slowly. Making three adjustments in two minutes is how an overshoot becomes an undershoot.
Next time
- Come UP to the target temperature slowly rather than overshooting and correcting.
Too much fuel was lit at the start for the temperature wanted.
occasionalSigns it is this one
- The intake is nearly closed and the temperature is still above target.
- A large quantity of fuel was lit at once at the start.
Why it happens: Closing the vents on an over-fuelled fire limits how fast it burns but cannot remove the heat already being released. The chamber comes down over a long time rather than quickly.
What to do
- Accept the higher band for this cook and plan around a shorter window, or remove fuel if the cooker's design allows it safely. — during cook, partial
Next time
- Light a small fire and add to it rather than lighting everything at once.