A 3D printer bed not heating up is an issue that many people experience when it comes to 3D printing, so I decided to write an article detailing how to fix this.
Keep on reading through the article to learn how to fix your 3D printer bed not heating up.
How to Fix 3D Printer Bed Not Heating Up
Here’s how to fix the 3D printer bed not heating up:
- Check for continuity
- Adjust the pins in the print bed connectors
- Check for burn marks on bed wires and replace
- Check for burnt connectors and replace
- Ensure thermal runaway has not been triggered
1. Check for Continuity
One method to fix your 3D printer bed when it does not heat up is to check for electrical continuity along the connecting wires of the heater bed.
For current to flow to your 3D printer bed properly, there must be no break along the path (wires) where it will flow.
If you notice that your printer bed is not heating up, you can use a multimeter to check for continuity along the wires. You can get the AstroAI Multimeter from Amazon if you do not have one.
Here are the steps to check for continuity on your heater bed wires:
- Ensure the printer is disconnected from the mains
- Power on the multimeter
- Turn the dial of your multimeter to the continuity range
- Touch the metal parts of the probes with each other. You should either get a loud beep from the multimeter or a value from the multimeter less than 1.
- Place both probes from the multimeter on both ends of the printer bed wires.
If there is a beep from the multimeter then the wires are okay, but if there isn’t, then there is a likely break along the path of the current (wire). To fix this, you either have to replace the wire or tighten it. Then repeat the continuity test until it passes the test.
The continuity range on your multimeter usually has a triangle with a line across it or a Wi-Fi symbol on it.
Here is a video from GalcoTV on how to test for continuity along a wire.
2. Adjust the Pins in the Print Bed Connectors
Another way that you can fix your 3D printer bed not heating up is to adjust the pins in the bed wiring connector
One user stated that he observed that his bed would heat up and then cool down after some time. After he wiggled the connector, it would start heating up again. He removed the connector and saw a blue tinge on one of the pins meaning it had been arcing (caused by a gap between the wire and the pin).
To fix this, he moved each pin outwards from their pin slots with a thin screwdriver to ensure it made a better connection with the wire, and has been fine since. Another user also confirmed that this worked for him.
It was described on his Creality CR-10, where at the back of the control box, there are two round connectors. The one at the bottom goes to the heated bed, so you disconnect that and take a close look at the pins.
One user said the cable going to the print bed had become so hot that he couldn’t touch it without burning his fingers, so it was lucky he noticed it in time.
3. Check for Burn Marks on Bed Wires and Replace
You can also fix your 3D printer by checking for burn marks on bed wires and replace it if you find some.
Once your printer bed stops heating up and you observe burn marks on the wires, you will need to replace the wires. You can cut off the affected part and solder them together as long as the bed can still reach the farthest point along its axis.
You can check out this video from 3D Print General on how to troubleshoot and fix your print bed when it is not heating up.
4. Check for Burnt Connectors and Replace
Another thing to do when your printer’s bed stops heating is to replace the bed’s burnt connector on the motherboard. Due to electrical surges or other electrical malfunctions, the connector for your printer bed may get compromised.
In most 3D printers, the motherboard is usually placed in an enclosure at the base of the printer. You just need a screwdriver to remove the screws on the metallic plate covering the motherboard.
Once you gain access to the motherboard, replace the faulty connector and reconnect the wires.
One user stated that his hotbed could not hold hot temperatures during printing. The temperatures drop and he gets a message saying “temp dropping, check wiring.” Then, when he tried preheating, it wouldn’t go past 26°C.
He ended up checking the motherboard and observed that his connector got burnt, he is now on the lookout for a better connector.
5. Ensure Thermal Runaway Has Not Been Triggered
A potential method to fix your 3D printer bed not heading up is to ensure Thermal Runaway hasn’t been triggered.
Thermal Runaway is a safety feature on 3D printers that ensures that your printer does not continue to heat up when it senses an anomaly in the 3D printer. This is usually triggered when the 3D printer does not sense any change in the temperature of the hotbed even when the bed continues to get hotter.
Thermal Runaway is usually caused by a faulty thermistor or a loosely connected thermistor. To counter this, tighten the thermistor’s connection and restart the printer.
One of the ways to certify your thermistor is faulty is to place a heat source close to it. If there is an increase in the temperature recorded, then it is likely working fine. If it does not record any increase in temperature after you have tightened its connections, then the thermistor is faulty.
If after you try all these solutions and the printer bed does not heat up, you may need to change the entire motherboard.
One user shared his experience with his CR-10 which was having Thermal Runaway errors during prints. He stated that the bed would drop temperatures from 65°C to 58°C before the thermal runaway error would pop up.
He unplugged and plugged in the cable for the printer bed and it heated up for a while, before displaying the Thermal Runaway error. He tried replacing the thermistor but it didn’t work.
Eventually, he discovered it was the power cable going to the heated bed (negative cable). He tried connecting it to a separate wire and the bed was heating up again.
Another user stated that he had Thermal Runaway triggered while he tried printing. He later found out that his heated bed power cable was faulty.
Here is a video from Creality on how to troubleshoot your 3D printer when its print bed does not heat up.