When you get this fault theres 2 thing that will cause this. Either a faulty heater or the control board.
The first thing to check is the control board. Remove the front outer door panel and then remove the plastic control panel. There you will see the control board. Reove this and open the plastic casing and remove the board. From there see if theres any dry joints or burn marks on there. If so try and resolder it as this usually works.
But if the control board looks ok then you need to pull the dishwasher out and remove the right hand side panel.
There you will see the heater in the bottom right corner. Check the wires on there and if you have a multi meter then you need to test the heater. It should read about 28 Ohms. If faulty then the heater will need to be replaced.
But if the heater is fine and the control board looks ok then you need to replace the control as it will be the heater relay on there thats failed and caused this.
If you need anymore info just get back to me.
hi could you tell me how much anew board should cost
Sorry for the delay in getting back to you.
The control board on this is about £130 so not a cheap part im afraid.