Bullet heating stalls over 190C

Hi guys,

Had a couple problem over the last roast, trouble shot some, still have some:

My roaster seems to have an heating issue: it stalls around 190C. When normally i had to lower the power to have a nice DT, now i have to rise the power to keep the ROR over 0 (see curve).

I currently have the error log :

Board V1.0 / Serial 1149 / Firmware 591
Info 29696: 152

Any one know if the heating element is due or something?



Did a roast directly after the one showed and the behaviour was closer to normal although form the roast level, I’d say the bean probe is under evaluating bean temp (got the bean out at 198 and it was looking like 210).

I only have the seasoning batches under my belt so I know less than a beginner. In the manual it mentions that v1’s need their IR glass cleaned from time to time?

@krame You’ll need to clean the IR sensor in the V2 as well. How often depends how dark you roast. If you always roast to dark (e.g. 2C) you’ll need to clean more often. Sweet Maria’s website has a very nice pdf with pictures for deep cleaning process.

@intelliespresso.bnCV not sure if you did a deep clean recently, but try that and see if it helps. I believe graphs for V1 Bullet is a bit different than for the V1.5 or V2. I think I read somewhere in these forums that in V1 it is primarily the bean probe that is used for reading temps. As for the error in the log best to contact support.


There is no heating element. The Bullets (V1/1.5/2) all have inductive heating. What needs cleaning is anything in the path of the exhaust starting at the faceplate, the transfer tube, chaff collector and the exhaust fan. Additionally you’ll need to clean the glass cover of the IR sensor (take care… I understand that glass cover is $$$).


Thanks all!

This roast was done right after a complete cleaning, hence why I was wondering if the heating might have been failing.

As @blacklabs pointed out my roaster takes the bean measurement from the bean probes, so the temperature might be rising without the bean probe noticing it! (that would explain why my roast is colour vs end temperature makes no sens, dark vs 196°C release) The roast would thus be stalling on the screen yet not in the barrel.

Could be a problem on your bean probe…BTW, what version of RT are you using

Everything seems to point towards it, might be the time to get the IR sensors if the board’s compatible…

And I’m on 3.4.1 (the latest right?)