Kamado won't heat, keeps dying or overshoots: fixes by symptom

When the thermometer sticks at 120-140 °C and goes no further, it is almost never a fault with the cooker: it is one of these five culprits, listed roughly by how often we see them.

1. Too little charcoal. A single thin layer never builds enough ember mass. Fill the basket to the rim; whatever is left over you reuse next time. 2. Damp or poor-quality charcoal. Lump that has soaked up terrace humidity lights badly and burns weak. Store it sealed and dry, and bin the dusty bags with no real lumps left. 3. Built-up ash. This is the silent killer: ash from the last cook coats the bottom grate and chokes the air from below. Empty it before every cook. 4. Vents nearly shut. Start everything strangled and the fire has no oxygen to grow. To climb, open both vents wide and close them as you near the target. 5. A cold deflector. The deflector's ceramic soaks up heat for 15-20 minutes before it settles. It is not refusing to climb — it is still charging. Give it time.

A kamado that keeps dying is a kamado starved of oxygen. Charcoal does not suddenly "run out": it stops getting air and suffocates. These are the three causes we have diagnosed over and over.

1. Air intake blocked by ash. By far the most common. Mid-cook, ash falls and gradually seals the bottom grate. Fix: with a glove on, give the basket a couple of taps or run a poker across the lower grate so the ash drops into the tray and air flows again. 2. Too little charcoal or a bad light. If you lit only one small spot and it never caught properly, the fire has no continuity. To guarantee the start, light in two or three spots and wait for live embers before closing the lid. 3. Bottom vent shut too tight. Below a certain opening the fire simply won't hold. For a 100-110 °C smoke, do not go under one finger-width at the bottom and leave at least the slots open up top.

Rule of thumb: if it dies, open first, don't close. The problem is almost always too little air, not too much.

The runaway kamado has the opposite problem: too much oxygen, and ceramic that builds momentum you can no longer brake on a dime. Here are the three causes, and why the lid is your worst enemy here.

1. Too much charcoal lit at once. Light the whole bed instead of one spot and you have a bonfire, not a controllable oven. For smokes, light only a small focal point (the Minion method); save the fully-lit bed for pizza or searing. 2. Vents wide open. Starting everything wide is fine for a fast climb, but lose focus and you jump from 150 to 280 °C in minutes. Start closing far sooner than you think. 3. Lid open too long. This is the flashback: with the lid open the embers gorge on oxygen, and when you close it that excess erupts into a sharp 40-60 °C surge. Open just enough, work fast, close.

On our terrace, nine out of ten runaways come from lighting too much charcoal or leaving the lid open chatting. The cooker is not faulty — we gave it too much air.

Bringing the heat down is the most delicate moment, because the ceramic holds its heat and reacts with a lag of minutes. If you have overshot, here is what works and, above all, what not to do.

1. Do not throw the lid open. It is the wrong instinct: you'd let cold air in for a second, then a gust of oxygen that reignites the fire. A closed lid is your ally. 2. Partly close the bottom vent — not all the way. Strangling the air from below is the real lever. But shutting it completely can put the fire out and leave you with nothing; keep a thread of air. 3. Anticipate: close 10-15 °C before the target. Because the ceramic keeps climbing on momentum, waiting until you arrive is already too late. In our tests, recovering from 250 to 150 °C took 30-45 minutes. 4. Once set, stop touching it. The classic mistake is correcting every couple of minutes: each touch adds lag. Close, wait ten minutes, observe.

Patience is the only tool that truly brings a kamado down. If you are in a hurry, you have lost: here the one who waits wins.

Most temperature problems are not fixed — they are prevented. A well-maintained kamado barely gives you a fright. These are the three habits we repeat on our terrace that cut ninety percent of failures off at the root.

1. Empty the ash before every cook. It is the most ignored and the most decisive. Ash blocks the air intake and causes both the "won't climb" and the "keeps dying" faults. Lift the grate, scoop the cold ash into the tray and empty it. Two minutes that save a cook. 2. Check the gasket and felt. Run your hand around the closed lid: if you feel heat escaping, the gasket is leaking uncontrolled air and you will never settle properly. Felt gets crushed and burns out over the years. 3. Seat the deflector correctly. Badly seated or with no air gap, it creates cold spots and false readings. Leave it level and with clearance from the grate.

A fourth tip worth its weight in gold: write down in a notebook where you set the vents when you nail a cook. That log prevents more failures than any expensive thermometer.

If you have checked air, charcoal, and ash and the cooker still won't obey, it is time to look at the material. The gasket and felt are consumables: over the years they crush, burn, and start leaking air, which makes holding low temperatures impossible. The telltale sign: you see smoke or feel heat escaping along the edge of the closed lid, and the kamado always overshoots your target. They cost around 20-40 € to replace and it is a fifteen-minute fix.

The ceramic is another matter. Fine hairline cracks from thermal shock are cosmetic and do not affect the cook. Only worry if a crack runs clean through and lets air pass, or if a piece has snapped: that is where you lose your seal. Most premium brands cover the ceramic with a long warranty, so check before paying for anything.

Use this table as a quick map from symptom to cause to fix: