ErC 6864


Oddly I’d had the issue since the Bullet arrived. Thought it was ‘normal’. Once the Bullet warmed up it seemed ok, but truthfully the lowest fan speed was getting slower & slower. If it ever warms up I can try a roast instead of speculating!



many thanks, Bruce
your suggestion help me !!


Just finished roasting with the new IBTS fan and all went well. Now that I see how it was supposed to operate I’m stunned it wasn’t a problem earlier. Wasn’t till the recent f/w change that it presented itself. The new fan operates ~16,1xx rpm with some small +/- variations.



Hi, there. I’ve been having some similar issues that I think are related to the IBTS fan. I’ve emailed support a bit, but wanted to chime in here too.

  • 11/24: Loud beeping when I power up roaster, screen not on so I couldn’t check erc
  • 11/24: Rebooted a few times, got to roast fine. Hear chirping/scratching noises coming from IBTS on startup, goes away during roasting when fan RPM is high
  • (went on vacation)
  • 12/2: Updated firmware and RoasTime, same issue but still able to roast after a few tries
  • 12/3 morning: Got Erc 6864 on startup, restarted a few times and was able to get the bullet running
  • 12/3 evening: Same Erc, able to roast after restarting a few times

How easy is it to access the fan to check it? I’ve taken the control panel front glass off, but am not sure what to do next.


It’s very easy to access but the lead lengths for 2 of the cables is very short. Take photos as you go so you can reattach anything that inadvertently comes adrift.

  • Remove the face plate (be careful of the cable for the speaker), then the
  • PC board (4 black screws); lift it to the side, then
  • 4 socket head screws that hold the control panel pedestal in place. To make it interesting there are 8 socket head screws to choose from. The ones you want are each on a small boss; the ones that are against a flat surface stay put.
  • At this point the pedestal is free but the 2 cables (plus the 2 blue wires) that pass thru the pedestal are really short; they lead to a single connector that attaches adjacent to the fan. It’s easy to detach unintentionally. The 2 blue wires are for the thermocouple and have no connector… be careful. Small cardboard boxes helped to support the weight of things that have cables still attached so the wires & connectors don’t get strained.
  • The IBTS fan should be visible now. There are 3 screws that hold it in place. Just remove these 3 screws and lift off the fan when you have the replacement. There is a tiny 3-wire cable that has to be disconnected from the connector board on the left. A pair of needle nose pliers helped.
  • If you did a good job documenting your way in, just follow the cookie crumbs back out and hope everything works once it’s closed up again. Check that all connectors are attached as you back out.

I won’t call it a piece of cake but it’s manageable if you take your time and document each step with photos. My new fan runs at 15,xxx - 16,2xx rpm continuously. The old fan would start at 4,xxx rpm and creep up a little as things heated up. Once I charged the drum fan speed went to 10,000 - 16,000 rpm and would drift around in that range. And the new fan is quiet by comparison to the old fan.


Help on IBTS fan replacement

I did all of that, fan looked fine, put it back together and now it seems to work? I’ll see if the error pops up on the next few sessions.

Also, that speaker cable is a pain to get back in the right spot to get the cover back on. :joy:


What IBTS fan speeds do you have at startup and when hot? I was told if it’s under 5,000 rpm there’s a problem.



I am troubleshooting the same thing.
Been have some strange problems lately, was advised to upgrade firmware to 540, did that…now have ERC 6864. Opened up the system, cleaned the IBTS noticed a lot of debris on the fan, cleaned it all up, put everything back together. Same thing. ERC 6864.

We are down hard.


ErC 6864 was introduced into the f/w recently. It measures IBTS fan speed. Not sure the failure criteria but I think fan speed must be above 4,000 rpm. If it drops below you get the failure. From my experience it isn’t going away till you get a new fan.

The smoke particles are thought to be from the cooling tray. @johnrathwell had the same issue and I think @jacob has said they’ve seen IBTS fans returned with the same contamination. My failed fan was spotless but was still failing. ( Wonder if mine was clean cuz it wasn’t moving much air… ?? )



I wonder where all that debris come from.
Did you check If the fan does spin at all? You can check the RPM in RoasTime and you should be able to hear it spinning as well.
If it is completely dead then you could try soaking it in alcohol. Never tried this but worth a shot until you get a new one.


Now I’m dealing with this too! I just caught it as I was getting ready to fulfill a bunch of orders! Thanks for all these good notes. Sent in a note to support and am going to try and take this a part and clean it to see if that helps.


Here’s what my fan looks like. Think this could be the problem?!


Update: took everything a part and cleaned the fan with rubbing alcohol and put it all back together with no change at all. It is still showing the error. Any thoughts on next steps? fw is up to date as well.


Wow! That stuff looks like tiny filaments that have grown from the fan & connectors & whatever else it can attach to. Yikes! There can’t have been much air velocity or the filaments wouldn’t have been able to grow to this length (they would have broken from the air currents). It’s like there was very little air motion. Yet there’s a fan spinning at over 15,000 rpm. Wish I had a clue what this is.

Edit- Just wondering out loud- I suspect I’m right that there was nearly no air flow thru the fan. That would allow filaments to grow undisturbed by air flow. When you get a replacement fan it would be interesting to confirm that the passageway beyond the fan going into the drum area is actually clear and not blocked.



Thank. I haven’t confirmed a replace fan yet, but hoping that happens soon. Will update once I have this worked out.



I really wonder how your IR fan can be that dirty. How do you went out the smoke?


I have an external exhaust fan I use that pulls the smoke out. My only thought is that I roast a decent amount each week, around 20 pounds?


You probably have it covered, but I have to ask: have you provided a supply of outside air to make up for the air the external exhaust fan pushes out? It’s easily overlooked, especially this time of year!



Sorry - it’s not connected, it is the oven hood. When I roast the bullet sits on my stove and I have the exhaust fan on above it.


My last two roasts I’ve had the 6864 error as well. On the last but one, I downgraded then upgraded the firmware (running 540) and had no problems.

This morning the machine booted, then about 30 seconds later I got the 6864. But the machine showed a countdown timer, starting somewhere around 20 (Maybe?). It alternated between Preheat Temp (235 in my case) and the countdown like this: 235 -14 235 -13 235 -12, etc. When it hit 0, the beeping stopped and I was able to preheat.

I have not opened the machine to look at the fan. (I replaced the IBTS assembly when I first got the machine as it was not getting power)

I religiously check fan speed (see parenthetical comment above) and indeed the fan speed starts below 4,000 - but then ramps up to between 11,000 and 15,000 - it is quite variable.

I’ll keep roasting, and try to collect more data on the next roast.