Bed heater thermistor replacement

So I have a B1 with bad thermistors and the one in the bed is the harder one to replace. You’ll need a new insulation pad for the bottom. it’ll be destroyed peeling it off. the thermistor is in a hole right in the middle of the bed and it looks like it’s potted in. bentonite maybe. I will put the new one in with a bit of thermal paste and then some bentonite grout on top and a piece of Kapton to hold it by the tires as the original was. then the new insulating pad. There’s nothing anywhere that described what to expect under a B1 bed so I thought I would post this here.

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so I’ve discovered this heated bed has solder pads for the thermistor wire to attach right near the hole. and the trace for those go to the edge of the bed where there are solder pads to hook the wires to. Also, the connections there at the wire/thermistor were a little melty because of the shrink tube, and actually, one side is open that’s why the thermistor isn’t working. should I just solder the thermister up and put the wire at the edge? or is there some reason this was a bad idea and they did it the way they did instead?


If its broken at the bed edge I would re-solder it back on not an issue. I am a little more weary about the hot bed contacts but the thermistor I would not an issue.

Actually it was never soldered to the bed edge. The wires go right from the motherboard all the way the hole in the middle of the bed.

oh gotcha, thats a new one for me, Usually is soldered pads center and edge or a wire taped to the bottom of the bed.

yup that’s it, the wire is taped to the bed and the connection on one side is broken where it’s connected to the thermister

ya unfortunately that’s a replacement.

Thermistor you mean? yeah, The parts haven’t arrived yet. SO you think I should use the solder pads on the bed or put it back the way it was ?

If it was me, check the 4 pads with a meter, confirm they are good and yes I would use those over wiring under the bed pad. 100%

I was leaning that way. The pads are good, I tested them when I realized what they were. and the parts for it just arrived so it should be running soon.

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