Bosch DW SMS69L02GB no heat

I was called to look at a Bosch dishwasher SMS69L02GB yesterday. Customer said it was “not heating the water, but doing the whole cycle however showing E02 on the display at the end of the cycle”
If I recall correctly E02 means “module failure”. I inspected the module closely but nothing visible. I do not normally attempt module repairs, unless it is an obvious dry joint (as with the older Bosch.Neff dishwashers)

Although I have been repairing Bosch/Neff DWs for over twenty years, this one is a new design completely and damned if I could find the heater to test it within the time constraints.
So I can go the obvious route of just buying in a new pre-programmed module. My reason for this post is to ask if anyone on the forum can advise me of how foolproof the E02 fault code is, and has anyone experienced other causes of no heat for this model. In other words should I go back, spend a lot more time dismantling the machine to get at the heater? Or just get a new module!
By the way, where is the darn heater?
Thanks for input chaps.