Hi.
I installed Octoprint in RaspBerry Pi 3 model with CR-10 3D printer.
The problem is that the temperature of bed shows 2000ºC 
Where is the problem?
Connect OctoPrint to the printer and In the terminal tab of OctoPrint, type "M105". Capture the output and post it here.
OctoPrint can only display what the printer tells it and it looks like the printer is telling OctoPrint that the bed temperature is 2000 degrees!
If you figure out why the printer isn't getting the bed temperature correct, then OctoPrint should fall into line. I'm guessing misconfigured firmware, bad wiring, or bad temperature sensor.
I have similar issue, but it intermittently happens when OctoPrint establishes connection to the printer. Bed temperature value spikes into thousands of degrees. Until that spike goes away, which takes about 25 minutes, the graph is useless. Would be nice to have an option of limiting the maximum value of the temperature that can be displayed let's say to 300 degrees.
Thanks.
What's on the printer displays?
Will need to check when it happens the next time.
I have VM8400MB mainboard from Velleman, but there is a good chance it has similar issue as CR-10.
Thanks.
I note that the Duet 3D printer appears to be reporting the exact same style of temperature (@ 2000 degrees).
I'm going to go out on a limb and suggest that the Marlin firmware for your printer was compiled with the wrong heater/thermistor or similar in mind.
You forgot "hot bed is inside operating kiln/furnace".
Or for the wrong board. I'm thinking that 2000C is a maximum or default value somewhere (perhaps a bad interpretation of a null or uninitialized memory) and the firmware for the Duet, at least, was pointing to the wrong GPIO or I2C/SPI device and getting an invalid or uninitialized value that is being misreported. In the second case, it could be the connection causing a brownout on the board that is causing an uninitialized device (ADC, thermocouple amplifier, etc.) to misreport until it is reinitialized.