Bosch was28466gb/01 heater failure

This is an interesting fault!
Bosch WAS series, perhaps other series too? Once in a while the heating element fails/goes open circuit and therefore has to be replaced. You must replace the heater with the correct heater for that machine but luckily the equivalent pattern part is just as good but just sticking anything in there as a replacement without a thermal fuse could cause a fire. Not all elements have thermal fuses within the heater though all plastic tanked machines will have.
What happens, briefly: so you`ve discovered the machine doesn`t heat the water anymore and you`ve sussed out that the heater is duff ( because its thermal fuse has blown ). On removing the heater any limescale seems burnt off and smells of burnt chalk and this is the key. What happens is the heater is coming on and receives a full 240volt input causing the heater to glow red WITHOUT ANY WATER IN THE MACHINE ON SPIN for about 30 secs until the thermal fuse inbuilt in the heater blows. I`ve come across this problem twice, but then I don`t see many Bosch machines prefering to work on much cheaper brands so it might be, might not be common. The cause is the £215.40 pcboard, a rip off priced part, £215.40 easily buys a new machine though of course not a Bosch. That, given this find of fault, is perhaps a blessing!