It gets more difficult now.
You could check out the pressure chamber shown in THIS
No heat can also be caused by low internal water flow due to the previously mentioned gunge. Also look at the top left hand corner of the large plastic fill chamber that covers most of the left hand (from front) side of the machine.
If there are signs of dark gunge blocking the tubes at this point then this can also cause this problem, this is almost impossible to clean out correctly.
If that is clear then its a matter of testing the heater with a suitable megger or multimeter. If the element is OK then it could be a PCB or wiring fault. Access to the heater etc is not very easy to say the least.
That which can be asserted without evidence, can be dismissed without evidence.