I have the same problem and I have not printed even one part with my UM2 machine :oops: due to Temp sensor error.
I opened the cover and I have found that as GR5 says, it seems that the problem is the pt100 sensor or its wirings. Hopefully I managed to buy a brand new sensor and when I plugged to the board it worked. But, I do not know how I can plug out the previous sensor probe from the hot end to replace it with the new one. Any idea? It seems that the probe is puched inside and cannot be removed easily. Please somebody advise.
Thank you very much