Just to add a bit to what @carefudundae said, the firmware in the controller board will register an error if no change in temperature is sensed after some period of time with the heater "on".
This is entirely normal behavior and indicates that your thermal runaway detection is properly working in the firmware, so that is a very good thing. 
You did not specify if you have an R1 (12v) or R2 (24v) printer.
If it is an R1 the bed resistance will be approximately 1/2 ohm.
If it is an R2 the bed resistance will be approximately 2 ohms.
The R1 bed heater draws a bit more than 20 amperes when on, which can cause problems on the controller board and its connectors, so look for melted solder or any signs of overheating in those areas.
The R2 bed will draw about half that, but it is still a lot to deal with for the on-board MOSFET, board traces and connectors.
After the problem is resolved you really should consider adding an external MOSFET booster board to handle the bed heater load (even on an R2).
Or change to a mains-supplied (110 or 220 volt as per your local supplies) bed heater with an SSR.
Either way it will relieve the loading on the switching components and connectors on the controller board and will heat faster.
I hope this helps.