There are quite a few threads on here for Neff/Bosch dishwashers not heating with 1 in the display so it might be worth searching the threads for the same problem but here are the 3 things to check for 1 in the display and running forever…..and these are in order of probablre causes
1. Water levels – check left hand side pressure chamber and hose for blockages – these will give low water levels which = no heat which = no cycle progression. This can sometimes be heard when appliance is filling by a kerdunk kerdunk noise and brief operation of the drain pump .
2. Burnt out contact on control module – If module has been changed thi is unlikely but still worth checking for bad joints on the board.
3. Open circuit water heater – right hand side – should be approx 23 – 33 ohms
Hope this helps
Paul