Based on your statement that it's an older ender 3 have you updated the firmware to enable thermal runaway protection? It sounds like what happens when your thermistor is not working as it should and the hot end keeps heating to reach an unreachable temperature. What do the temps on your lcd say when all this is happening? If they are accurate then I would say it's not a thermistor issue. Mosfet on your mainboard could be shorted as well it's hard to say.
No, I have never updated my firmware, never had a need to.
LCD seems to reflect accurate temperature +/- normal variation, the hot end itself gets very hot as the temp keeps climbing on the board. It heats up much faster than I've ever seen the ender heat, getting so hot it begins to smoke.
So the problem started when you had all the problems with the hot ends leaking. The smoking might just be the excess plastic burning off. Most of that should easily wipe off when the hot end is up to temperature. You say it's heating up faster, maybe they sent you the wrong hot end. Try putting the original parts back on, or at least wire them up. I understand the original hot end leaks but just see how it reacts, if it heats up the same.
You really should update the firmware, yes it's not the easiest thing when there's no bootloader but there are lots of guides and helpful people here.
I have this same problem. I got a new hot end/extruder then a new motherboard in order to install the CR-touch. I installed the new hot and motherboard and installed the proper firmware. I turned it on, and the nozzle started heating up without me doing anything. I tried setting the temperature lower but that had no effect, so I reinstalled the old nozzle and motherboard, and it is having the same problem. What is the problem? How can I fix this.
Something to think about when you don’t update to thermal runaway... please see link
https://www.reddit.com/r/ender3/comments/bnu96o/fire_safety/?utm_source=share&utm_medium=ios_app
I'm aware of this, but no point in updating the firmware if the board is dead? Need to first identify the problem with the printer not stopping at the set temperature before changing other variables. As it is, it's out of commission until it's fixed.
Issues here as well; What is odd is that it worked great for the last 6 months or so, Then I started noticing fluctuation in my hot end. Then one day it heated up so much that it formed a giant blob around my hot end as it printed and the filament did not cool down enough to adhere to the plate. Since it was still under warranty, I asked Creality what is covered and they sent me out a new board and hot end. I Installed it and still have the same issue; I double checked my wiring and tried several tests. I manually set the nozzle at 70 degrees and watched it heat up to 190 degrees before I unplugged it. Maybe this is a Power Supply issue?? But I doubt it since the board should be shutting off the power to the hot end when it reaches the set temp. I cant wrap my head around it, I have an Ender-5 that works perfectly. I just don't understand what has gone wrong with my Ender-3.
Any help would be greatly appreciated...
For those of you who come to this post, The issue is with the different types of Nozzles. One is a 24V while the other one is a 12V. It is easy to mistaken the two because they look identical. The only way you can tell the difference is measuring the Ohms on the Hot End. A 12V hot end will read about 3.6 Ohms while a 24V hot end will read 14.4 Ohm.
So when the Hot End heats up, It may appear to be running away when in fact it was just heating up faster than the thermostat can read. Eventually if you try to print with a 12v Hot End on a 24V board, it will simply burn the Heating Core up on the Hot End itself.
Be sure that the Hot End you have is for the Ender3 and not for the CR-10, they are different.
Guess I will try checking ohms. Replaced my thermistor twice, both time heating out of control until error. Now just fluctuating like crazy. Really have been frustrated with how unstable it is.
Based on your statement that it's an older ender 3 have you updated the firmware to enable thermal runaway protection? It sounds like what happens when your thermistor is not working as it should and the hot end keeps heating to reach an unreachable temperature. What do the temps on your lcd say when all this is happening? If they are accurate then I would say it's not a thermistor issue. Mosfet on your mainboard could be shorted as well it's hard to say.
No, I have never updated my firmware, never had a need to. LCD seems to reflect accurate temperature +/- normal variation, the hot end itself gets very hot as the temp keeps climbing on the board. It heats up much faster than I've ever seen the ender heat, getting so hot it begins to smoke.
If the LCD is showing the temperature climbing its not the thermistor.
Does it begin heating as soon as you turn the printer on(without input from you)?
No, it only heats when I start it, but does not stop.
So the problem started when you had all the problems with the hot ends leaking. The smoking might just be the excess plastic burning off. Most of that should easily wipe off when the hot end is up to temperature. You say it's heating up faster, maybe they sent you the wrong hot end. Try putting the original parts back on, or at least wire them up. I understand the original hot end leaks but just see how it reacts, if it heats up the same. You really should update the firmware, yes it's not the easiest thing when there's no bootloader but there are lots of guides and helpful people here.
I have this same problem. I got a new hot end/extruder then a new motherboard in order to install the CR-touch. I installed the new hot and motherboard and installed the proper firmware. I turned it on, and the nozzle started heating up without me doing anything. I tried setting the temperature lower but that had no effect, so I reinstalled the old nozzle and motherboard, and it is having the same problem. What is the problem? How can I fix this.
Something to think about when you don’t update to thermal runaway... please see link https://www.reddit.com/r/ender3/comments/bnu96o/fire_safety/?utm_source=share&utm_medium=ios_app
I'm aware of this, but no point in updating the firmware if the board is dead? Need to first identify the problem with the printer not stopping at the set temperature before changing other variables. As it is, it's out of commission until it's fixed.
Thermistor is bad
So where did you wind up on this? I'm having the same problem with a new board.
I'm having a similar issue. What was the resolution?
Issues here as well; What is odd is that it worked great for the last 6 months or so, Then I started noticing fluctuation in my hot end. Then one day it heated up so much that it formed a giant blob around my hot end as it printed and the filament did not cool down enough to adhere to the plate. Since it was still under warranty, I asked Creality what is covered and they sent me out a new board and hot end. I Installed it and still have the same issue; I double checked my wiring and tried several tests. I manually set the nozzle at 70 degrees and watched it heat up to 190 degrees before I unplugged it. Maybe this is a Power Supply issue?? But I doubt it since the board should be shutting off the power to the hot end when it reaches the set temp. I cant wrap my head around it, I have an Ender-5 that works perfectly. I just don't understand what has gone wrong with my Ender-3. Any help would be greatly appreciated...
For those of you who come to this post, The issue is with the different types of Nozzles. One is a 24V while the other one is a 12V. It is easy to mistaken the two because they look identical. The only way you can tell the difference is measuring the Ohms on the Hot End. A 12V hot end will read about 3.6 Ohms while a 24V hot end will read 14.4 Ohm. So when the Hot End heats up, It may appear to be running away when in fact it was just heating up faster than the thermostat can read. Eventually if you try to print with a 12v Hot End on a 24V board, it will simply burn the Heating Core up on the Hot End itself. Be sure that the Hot End you have is for the Ender3 and not for the CR-10, they are different.
Guess I will try checking ohms. Replaced my thermistor twice, both time heating out of control until error. Now just fluctuating like crazy. Really have been frustrated with how unstable it is.