UM2 Bed Temperature reading higher than actual temperature

[idesignmake 0]

Hi All,

 

There are probably loads of topics covering this, so if you could link them that would be great.

 

OK, basically, the displayed temperature for the bed is reading higher than the actual temperature of the bed.

 

What could be the cause? and how can I fix it?

 

Cheers

[geert_2 556]

The cooling fan blows cold air onto the model and glass. In my tests this could give a local difference of up to 15°C on the glass plate for small models. This could be a major source of difference, as the sensor is at the bottom of the glass, not the top.

 

[idesignmake 0]

Hi,

 

thanks for the reply.

 

the issue i'm getting is with the printer at idle with the bed lowered.

 

the temperature is currently showing as 39degC when the temperature is 0degC. this can vary up to 60degC

 

my room is definitely not 39degC 😅

 

thanks,

[geert_2 556]

Is the printer still cooling down from before, or is it just always? It may take quite a long time to cool down, depending on the situation, the airflow, and the bed-temp of the previous print.

 

Or could it be heat transfered from the electronics below, or a nearby heater, or sunlight? Behind a window in the sun, it can easily be 60°C, like in a car.

 

I would say: in the morning, after being off for the night, measure the temp before switching it on. Then, without printing, measure again after half an hour or an hour. It should still be about room temp, maybe a little bit more. Shut off windows or other heat sources. I think that could give you an idea if the electronics are fried (short circuit or so).

 

[idesignmake 0]

Hi,

 

The temperature reads 39 as a baseline, even after a night of cooldown, the room temperature is stable, the printer is not next to a particularly strong heat source or draft.

 

I've been searching through the forums and it seems this is not an uncommon issues, it seems the connections on the heated bed are usually the culprit.

 

https://community.ultimaker.com/topic/3436-a-fix-for-ultimaker-2-heated-bed-not-working/page/2/

 

i'll do a bit more investigation when the new multimeter arrives.

 

thanks for your help.