If thermal runaway is displayed
If "Thermal Runaway" / "Thermal Dip" is displayed
During roasting with the Kaffelogic Nano 7, "Thermal Runaway" or "Thermal Dip" may be displayed and the roast may stop. This stop is usually not a malfunction, but rather the result of the safety device functioning correctly when an abnormal condition is detected during roasting.
Main causes (important)
This error occurs when heat is not properly dispersed within the roasting chamber and is judged to have accumulated at the bottom due to a combination of the following conditions during roasting:
The three most common causes are:
- Beans not circulating properly and accumulating at the bottom (poor circulation/bean lock)
- Weak airflow (insufficient fan speed)
- Rapid increase in Rate of Rise (RoR)
Bean Circulation
Among these, the most important factor is whether bean circulation (airflow) is adequately maintained. Please be aware that this is particularly prone to occur under the following conditions:
- Light roast
- High-density beans
- Large beans (e.g., Kenya AA)
Please refer to the following page for instructions on how to use the fan preview function.
https://kaffelogicjp.com/pages/fan-preview
Please use the fan preview function to check if the beans are circulating properly.
About ROR (Rate of Rise)
Another factor contributing to thermal runaway, especially when using self-created profiles, is an excessively high Rate of Rise (RoR). This can also be considered a cause.
https://kaffelogicjp.com/pages/studio_guide_RoR
In cases of thermal runaway occurring when roasting with your own created profiles, "excessively high RoR" is one of the causes of the stop.
How to deal with an error display
- Press the ▶ (Start/Cooling) button on the unit.
- Wait until the cooling cycle is complete.
* Since roasting has stopped midway, the beans at this point will have significant unevenness in roast, and are generally not recommended for consumption.
Improvement points during roasting
-
Check bean circulation (most important)
Use the fan preview function to check if the beans are circulating properly.
https://kaffelogicjp.com/pages/fan-preview
-
Adjustments for weak circulation
If circulation is insufficient, adjust the following:
→Reduce the batch size
→Increase the fan speed (airflow) -
Check RoR (Rate of Rise)
When creating your own profile, check the RoR to ensure a steady temperature increase. Adjust the profile as needed.
https://kaffelogicjp.com/pages/studio_guide_RoR
Checklist for recurring errors
Please check the following items in order from top to bottom.
① Unit Installation Environment
- Is it placed on a hard, level surface?
- Are the air intake and exhaust vents unobstructed?
② Chaff Collector Cleaning
- Empty the chaff (silver skin) before each roast.
- Clean the mesh holes on the lid with a brush or similar tool.
Oil and fine particles can significantly reduce airflow, more than it appears.
③ Firmware Check
- Update to version 7.17.10 or higher.
- * The latest firmware reduces the occurrence rate of this error.
⚠ In rare cases, smoke or charring may occur
Although extremely rare, beans accumulated at the bottom may smolder or ignite.
In such cases:
- Turn off the power using the wall switch.
- Cover the top of the chaff collector with a pot lid or similar.
- If possible, take it outdoors and allow it to extinguish naturally.
* If the abnormality persists, please contact official support.
Possibilities other than Bean Lock
The same error may occur in the following cases:
- Deterioration or failure of the heater element
- Weak temperature rise during dry roast test
- Error occurs even under standard conditions (120g, Classic profile)
👉 In these cases, component replacement may be necessary.
Please prepare the following information and contact support:
- Roast logs (saved data) - Please send 10-20 past roast logs via email.
- Profile used
- Roast quantity (g)
- Timing of error occurrence