Recv: ERROR: MINTEMP or MAXTEMP triggered on BED

(Brandon Cramer) #1

I keep getting this error on my Eustathios Spider V2. Is this a thermistor issue or do I need a new heated bed? If I M999 a couple times I can get it to heat up and print something.

Recv: ERROR: MINTEMP or MAXTEMP triggered on BED. Check your temperature sensors!

Recv: HALT asserted - reset or M999 required


(Brandon Cramer) #2

One other thing is in Octoprint, the bed temp doesn’t show up under the temperature tab like the extruder does. Under terminal I can see the temperature still.

(Eric Lien) #3

One option is to measure the heated bed thermistor resistance with a multimeter (disconnected fry the printer). There are temp tables you can Google, and compare temp to resistance. It might give you a clue if it is failing. Also, as always, check your wiring for potential issues.

(Brandon Cramer) #4

I’m always printing in the garage where it’s currently cold. Could that have anything to do with it?

I will try what you suggested. Isn’t the thermistor built into the heated bed? Would I need to purchase an entire new heated bed and thermistor from AliExpress?

(Eric Lien) #5

I had one of my earlier their thermistors go bad on one of my earlier heated beds, that’s why now I recommend putting a hole in the middle of the heated bed so you can attach it through the pad directly into the aluminum below but be able to easily replace it. You can remove the heated bed pad if you’re really careful and then apply a thermistor underneath and then reattach the pad with some 3M 468MP high temp double sided tape.

(Eric Lien) #6

Like this is how I do it now

(Brandon Cramer) #7

Are you cutting this out of mdf? Laying down the heated bed, thermistor, aluminum, and glass?

I ordered a new heated bed. Just curious if I should do the above to help maintain the temperature.

(Eric Lien) #8

That picture was of the heated bed pad itself.

On HercuLien I use an MDF insulator. On Eustathios I use simple cork to insulate the buttom.

(Dennis P) #9


What firmware are you using?

With Marlin, you can enable it to spit out the actual ADC values so you can build you own custom
thermistor tables.

It shows up in the terminal display under Octoprint.

The thing is you need to correlate the actual temps to those readings.

I bought a known thermistor with known good datasheet from digikey, based on the predefined list of thermistors.

Its not a cheap as buying from ali or gearbest, but the wait time and elimination of questions and headaches was worth the $4 in shipping.