Thermal Error with blank Heater_ID


I’m not very experienced with the Taz 6 or 3D printing in general, but I support three of these things and manage them with OctoPrint. After three months of trouble-free printing, one of the Taz 6’s has begun to throw thermal errors, but the error does not indicate the problem’s source. See below for a log snippet.

Besides testing the bed’s and toolhead’s thermistors and checking to make sure all connections are secure, what else can I do to diagnose the problem? These printers are pretty much in constant use, as we offer free printing of models for students, and I’d like at least to attempt some troubleshooting before giving up, requesting an RMA, and then being down one printer for a few weeks.

Thanks for whatever suggestions anyone may have to offer.

2018-02-04 15:32:25,894 - octoprint.util.comm - WARNING - Received an error from the printer's firmware: Thermal Error, system stopped! Heater_ID: 

| Last lines in terminal:
| Send: N5668 G1 X238.862 Y175.382 E557.82421*90
| Recv: ok
| Send: N5669 G1 X238.697 Y176.429 E557.86835*87
| Recv: ok
| Send: N5670 G1 X238.318 Y177.417 E557.91241*94
| Recv: ok
| Send: N5671 G1 X237.804 Y178.209 E557.95172*87
| Recv: ok
| Send: N5672 G1 X237.740 Y178.306 E557.95656*84
| Recv: ok
| Send: N5673 M105*16
| Recv: ok T:210.1 /210.0 B:39.9 /60.0 T0:210.1 /210.0 @:77 B@:103
| Send: N5674 G1 X236.992 Y179.054 E558.00061*86
| Recv: ok
| Send: N5675 G1 X236.202 Y179.567 E558.03983*86
| Recv: ok
| Send: N5676 G1 X236.105 Y179.630 E558.04464*83
| Recv: ok
| Send: N5677 G1 X235.116 Y180.010 E558.08876*82
| Recv: Error:Thermal Error, system stopped! Heater_ID:

The temp report shortly before the error (Recv: ok T:210.1 /210.0 B:39.9 /60.0 T0:210.1 /210.0 @:77 B@:103) shows that the toolhead is at target temperature, but the bed is >20 below target. That points to the BED as the problem, not the toolhead.

The bed not reaching/holding temp could be a bad bed thermistor (i.e., bed really is hot, but temp is reading low). It could be a bad bed heater (but those are pretty reliable). It could be bad wiring or plugs. It may also be a broken wire in the bed cable chain – particularly if you see the drop when the bed is moved to certain positions.

Thanks ScottW, that’s helpful. I should’ve read the log closer and noticed that temperature problem! :blush:

I didn’t have an extra set of hands today to wiggle the bed harness while I held the multimeter, but I’ll give that a shot Monday. I did unfasten and resecure all of the connectors and tested the thermistor, which looked ok, but again, I was all alone and wasn’t able to have someone put some movement into the wires. I also noticed that the table supporting the printer was at about a five degree angle and corrected that. It’s possible that might have aggravated a loose connection somewhere.

Anyway, thanks again. That got me started, which is what I needed.

Glad to help!

That error message is supposed to have either an extruder number or the word “bed” at the end. Not sure why it doesn’t… Do you know what firmware version you are running? The current code appears to always output the error source, but perhaps older versions had a bug there.

Good luck, hopefully the problem will be easy to pin down.

I did a pretty thorough test of the wiring between rambo, bed, and toolhead, and all looks well, as did the thermistors. We haven’t seen any problems after I re-secured all the connections and cables (and leveled the table!), so it looks like that was our problem.

Thanks for the tip on the firmware: sure enough, we’re a little behind (Marlin vs., so that update is in the works as soon as I can get a couple of hours or so of downtime to apply and test.

I appreciate the suggestions, ScottW.

Which extruder? Are you noticing dropouts in the Octoprint temp graph? Lulzbot just announced that the cartridge thermistors for the Aero, MOAR, Dual v3 hotends might have issues with the crimping of the pins. Look for the recent service announcement.

Re-crimping the cartridge thermistor pins with pliers could be a fix if you don’t want to send the toolheads back. Pop the pins out by depressing the middle silver tab/dot on the connector housing. Squeeze the sides of the crimps near the wire insulation with pliers.