Smoke not Venting


Yakster, I sure do, but thanks for checking.


Sounds like the impeller fan may be going in the wrong direction. I’d check with Aillio, not sure how the direction would get reversed, but if it were possible to plug in the fan reversed with the connector that may do it.


Thanks Yakster. I have had quite a number of normal roasts so it’s weird that it only happens periodically. I would be really curious to hear from someone who has a chance to open the chaff collector and see which way their fan is spinning.


I did a quick check on the exhaust fan. Mine is turning CCW and I have exhaust exiting in all the right places. (I will never understand how blades on a centrifugal fan work. I got this wrong in 1972 to the tune of $150 to reverse my error.)



Maybe a stupid question, did you clean the stainless steel basket in the chaff collector. When I see smoke coming out the trier hole it has always meant the basket is getting clogged. Take it out and soak it in Cafiza to clean.


I should have thought of that… 15 roasts is about the limit for my roaster. I wire brush the filter but Cafiza is probably a better non-abrasive choice.



I have been cleaning it with a brush but will do a deeper cleaning and let you all know if that works. Thanks again for all the input. What an amazing community!


This has happend to me before. When the filter gets blocked up. The steam and chaff clog the filter and then you get back pressure. When you leave it over night it dries out and on the next roast will work for 1 of 2 roasts before it starts again. I clean it after every 5 kg.


Very interesting. That just might be my problem. I did a thorough cleaning and so far it seems okay. I will post again if I have issues. Thanks again to everyone for your help.


I just did two roasts back to back at about 450 grams each. Since the machine was hot, I did not empty the chaff collector between roasts. Everything was going along swimmingly until the last minute of the second roast. When I pulled the tryer, smoke started billowing out of the front of the machine. Do you think I just need to empty the chaff collector? I’m at a loss to what else might be happening. My machine vents to the outside of my house as you’ll see in the attached picture. 59416498333__88B4AE81-2C2F-4B99-A8FB-045006D4164F

I subsequently cleaned the chaff collector and tried another roast and it worked just fine. So perhaps that is all it was.


UPDATE! I have been cleaning the chaff collector after each roast and this seems to have solved my problem completely. Which raises the question: When doing back-to-back roasts, do others clean the chaff while the machine is hot?


I never intentionally stop the roaster between roasts. I believe I was warned not to power off the roaster when it’s still hot as the residual heat can damage wiring with the exhaust fan stopped. [ We need input from @jacob about this ] I always vacuum the chaff collector after a roast session (3-5 roasts of 550g each) and (in the past) at a minimum check the basket after 2 roast sessions. If I don’t see a lot of light thru the filter it gets cleaned. However…

I had an instance where the the filter in the chaff collector became clogged thanks to a lot of fine chaff and what I guess was oily residue (or maybe moisture from the drying phase). The filter basket was so clogged after 2 roasts the exhaust fan was literally pulling the basket out enough to contact the fan. That slowed the fan a lot so that, between the clogged filter and the drag on the fan, the air flow got so low it overheated the roaster. The rubber had become so soft from all the heat (not enough air moving thru the filter) that the filter basket just wouldn’t stay seated and would sag down enough to touch the rim of the fan impeller.

Since that occasion I’ve made it a point to carefully seat the edge of the filter basket inside the inner groove in the EDPM filter basket mount. But seating the filter basket in the groove won’t help if the filter becomes clogged with debris. If you’re mid-roast, there’s not much choice but to dump the chaff and clean the filter basket so you can get air moving again and cool the roaster properly.

Since the problem above I have started pulling the filter basket after every session to be sure it isn’t clogged with fine particles. This is contrary to the general maintenance guidelines Sweet Maria’s presented in their video back in Jan or Feb.

Btw, I had gotten the over-temp ErC so there was no continuing the roast at that point. I’ve never tried roasting those beans again!

I can’t recall: have you calibrated your exhaust fan recently? I wonder if the calibration data has somehow become corrupted and the fan isn’t running as fast as it should. Only takes a few minutes in Off mode so it doesn’t require heating the roaster.



Thanks for the response. I looked at the filter basket and it wasn’t seated deeply so I pushed it in a bit harder. Sounds like a good thing to keep an eye on regardless. I have never calibrated the exhaust fan and will try doing that tonight. So far things seem to be going well, but I appreciate all the thoughts and feedback.



I clean the filter basket after every roast session (4 - 6 roasts). I also vacuum out the chaff collector after each session. It really depends on the type of bean you roast. I roast a lot of dry process beans, which generate a lot of very fine chaff. I can run longer with wet processed bean from which the chaff is much larger. To be totally honest I laze out and clean them before I start roasting. I agree with Bruce, calibrate your fan. Hope this helps.


Similar to Dr-D, I always vacuum after all roasting is complete and I usually do two 1lb roasts back to back. Some beans produce a lot more chaff than others, but unless you are doing a lot of full-load (2lb) roasts back to back, you should be just fine vacuuming once after each roasting session. The Bullet’s chaff collector holds a lot of product.

On the filter basket cleaning, that just depends on how much you roast and how often. I just roast for personal use and do 2-3lbs about every 10 days. In that kind of use, I only need to clean the filter basket about every 5th use. I always vacuum the filter basket in addition to other areas of the Bullet after roasting. When the basket starts getting dingy, I drop it (and the impeller fan) into a 2qt glass Pyrex with hot water and 4-squirts of Urnex. Let is sit for a few hours and everything is clean without any scrubbing. The best-practice with cleaning this stuff (especially with coffee roasters) is not to allow it to get so dirty that it takes a lot of effort to clean.

Have fun with your Bullet!


My problem persists, so I pulled off the chaff collector during a roast to see what was happening and discovered that my fan periodically stops turning. I think I’ll need to open a ticket with Aillio, but thought I would check here in case someone has a suggestion. See video links.


May be a dumb question, because it appears you have a new Bullet (w black handle), but does it have the larger chaff filter? This is the one that is about 4 inches long, and not the dome shaped one that is about 1-2 inches long.

The newer ones last a few roasts between cleanings.



That is not right. Definitely open a ticket with Aillio. My bullet never did that.


Thanks Steve. I have done that and will post back with updates.


Apparently not a common failure, but mine had to be replaced too. Mine made it only a couple weeks.