Hello Jigsaw,
I would suggest that the heater control board in the bed of the machine has failed, this board controls all of the heaters in the machine.
Is the machine still under the 5 year warranty ? . I would power the machine down completly at the mainpower switch when not in use until you get this fixed.
Don't leave it powered down for more than 24hrs at a time, turn it back on so it can still do its maintenance, then power it down again. If the heating element in the bed burns out it cannot be replaced.
Cheers
Brett