Error on Heaters



  • M307: Heater 1 appears to be over-powered. If left on at full power, its temperature is predicted to reach 521C

    Keep getting this error on both heaters.

    ; Heaters
    M308 S0 P"temp0" Y"thermistor" T100000 B4008 ; configure sensor 0 as thermistor on pin temp0
    M950 H0 C"out0" T0 ; create bed heater output on out0 and map it to sensor 0
    M307 H0 B0 S1.00 ; disable bang-bang mode for the bed heater and set PWM limit
    M140 H0 ; map heated bed to heater 0
    M143 H0 S120 ; set temperature limit for heater 0 to 120C
    M308 S1 P"temp1" Y"thermistor" T100000 B3950 ; configure sensor 1 as thermistor on pin temp1
    M950 H1 C"out1" T1 ; create nozzle heater output on out1 and map it to sensor 1
    M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
    M143 H1 S300
    My config.g part. I did PID tuning on both


  • Moderator

    @mrenz999 said in Error on Heaters:

    M307: Heater 1 appears to be over-powered. If left on at full power, its temperature is predicted to reach 521C

    It's not an error, it's a warning.

    You may receive this warning after running a PID tuning when the tuned PID values are loaded at startup. It is an informational warning telling you what temperature the firmware algorithm suspects the heater is capable of reaching in a full power runaway heater situation. It is meant to encourage you to either choose a less powerful heater that is physically unable to reach such a temperature, or to take precautions to mitigate the effects of an uncontrolled heater situation, such as adding a thermal cut out spec'ed appropriately to cut power to the heater if a temperature is exceeded. At the very least, do not leave your printer unattended, have a smoke detector present, and have a fire extinguisher handy.



  • What is the threshold for getting the warning?

    I have it on an E3D V6 with 30W cartridge, which is not normally considered an overpowered setup, though it is a copper block, so presumably has under half the specific heat of the more normal aluminium.

    My config has 'M307 H1 A550 C330 D3 S1 V24 B0', which is pretty much the average of three M303 runs.


  • administrators

    @achrn said in Error on Heaters:

    What is the threshold for getting the warning?

    (Tmax - 25) * 1.5 +50

    Where Tmax is the temperature limit set by M143.



  • @dc42 said in Error on Heaters:

    Where Tmax is the temperature limit set by M143.

    Aha, that would explain it - I have my M143 set quite low (just above what I'm actually printing at) in order that my 'temperature chart' in the web interface doesn't have a load of empty space above the line. Thanks.


Log in to reply