ErC 6864 is there a fix or is a new fan required

Over the last month when plug in the Bullet to start, I can hear a very very faint high pitched whine coming from the face plate area. After a few minutes the sound would disappear. On my last roast yesterday, the same thing but this time I got an ErC 6864 error and the roaster powered down during preheat. I waited a few minutes and tried again after the whine disappeared. This time no problems. I looked up the ErC 6864 and apparently this indicates an IBTS fan speed too low. I have a trouble ticket sent to Aillio on this but I thought that I would try this forum to see if there is any fix while waiting for the trouble ticket answer. Here is my “gut” take. I have worked on computers and when I notice that when a fan is about to go bad, the bearings go out and a whine is heard for the first few seconds until the fan gets going. Eventually the fan dies, however. I wonder if this is the case with the IBTS fan? Is there any easy fix or cleaning that can fix this or is the fan about to go out and I need a new one? Again, waiting on Aillio tech support but thought I would see if anyone else has had this issue.

You can see IBTS fan speed in the Info panel. When mine died it was below 5,000 rpm (that’s what Bullet f/w tests to decide if it’s working). I found my nearly dead fan would gradually creep up above 5,000 rpm and limp along at that barely-acceptable rate. About the time the fan couldn’t make it up to 5,000 rpm any more the replacement fan arrived. It was a shocker to see that the replacement fan was operating at 16,000 rpm.

You may need one or more replacement rivets for holding the fan in place… they’re easily damaged.


Thanks. I didn’t check it early on in the “whining” phase. But once I started a roast successfully the IBTS fan was always 14000 to 16000 range.

Mine got faster as it warmed but never close to a normal range. Losing a batch mid-roast was the last event I recall. No issues with the fan since. They get some infant mortality with the fans but they seem to be durable once the bad-actors are weeded out. One user that had the same problem at around the same time had a fan covered with white “dust” (smoke residue) yet mine was virtually spotless. Odd the difference yet they both died the same way at about the same age.


Matt from Aillio was very helpful. It was a fan about to go bad. Early idle rpm was 6000. I got the replacement form Sweet Maria’s. The install video from Aillio was very helpful. Now idle rpm is back to normal 12000+, no alarm and no whining noise. This is a great roaster with great support.

I’m getting the same error and my machine is shutting down. Where to get a replacement fan? And how do I keep this from happening again? I’m guessing that the fan gets gummed up over time

The fan placement is pretty good to avoid contamination. Air is drawn in at the base of the pedestal where the Control Panel is mounted. Air is blown downward toward the IR sensor to keep the viewport clear of smoke & chaff. If you roast pretty dark, roasting snot will still collect as the smoke can drift up toward the pedestal base and get picked up in the draft created by the fan.

To mitigate the issue some use an external fan separate from the cooling tray to keep the smoke away and at the same time offer air movement around the power board mounted below the drum.

The fan can have ‘infant mortality’ (early failures) and I was one of those that had to replace a fan. The speed had dropped off below about 5,000 rpm; nominal speed is 16,000 rpm. There were a couple roasters reported to have been built with the fan installed in reverse but I will guess that’s been long since resolved.

Easiest way is to start a Trouble Ticket on → Contact and they’ll guide some trouble shooting and get a fan on the way to you from your dealer or from Aillio. Dig/search here to find some images describing the replacement process.

There is some maintenance required for the IR sensor. Even with that tiny fan screaming away at 16,000 rpm there is still ‘stuff’ that attaches to the lens of the IR sensor. I keep track of the difference between I-temp and B-temp at around B-temp = 225°F. If the difference falls off to less than 40F° I know it’s time to clean the sensor lens.

Aillio recommends alcohol so I clean with a cotton tipped swab. Unfortunately I have never seen anything come off onto the swab. But if I make about 4-6 passes I can see a difference during the next roast… temp difference will be back to 41-43F°.

The temp difference (I-temp - B-temp) is dependent on batch size. If you use smaller batches than the 550g batches I roast, the temp difference will be greater than I see. Conversely if you use a 1 kg batch, the difference when clean will be less than what I see. It takes a little experimenting.


Thanks- new fan on the way. Random shutoffs are the worst.