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 least 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.