Thermal Runaway
I am getting a thermal runaway error on almost every print I am doing now. I had to replace the thermistor on my MK3 I3 because I damaged it. I replaced it with an E3D thermistor and had no issues for about a week. Now it seems like any print that lasts more than an hour or so I will get the thermal runaway error. I did have the printer in my basement where it stays much cooler than the rest of my house and I know that can be an issue at times so I moved the printer up to a spare bedroom and tried printing again and still got the thermal runaway error after about 2 hours of printing. Any ideas on what might be causing this issue?
Re: Thermal Runaway
A thermal runaway error is caused when the heater can't keep up with the required temperature. This is a safety feature, in case there's a fault in the temperature sensor that causes it to read too low the printer will shut off before something gets too hot.
I've had a couple thermal runaway errors when I tried to combine too much cooling and a relatively high bed temperature. With the cooling fan on 100%, the bed can't maintain much over 90C, and so trying to have a 100C bed with 100% fan will trigger a thermal runaway error.
I suggest you try turning the bed temperature down or reducing the cooling fan. An enclosure (box) will help, too.
Re: Thermal Runaway
Tried your suggestions, still no success. I believe it has to be a bad thermistor again... there are times I can preheat the nozzle and it will never fully heat up according to the display screen, but it smokes and burns the filament inside the nozzle.
Re: Thermal Runaway
Tried your suggestions, still no success. I believe it has to be a bad thermistor again... there are times I can preheat the nozzle and it will never fully heat up according to the display screen, but it smokes and burns the filament inside the nozzle.
That definitely sounds like a bad sensor. If the printer thinks the nozzle is too cool but you see smoke coming out, that's not good.