We have a 3 1/2 year old Bosch dishwasher, which yesterday stopped draining correctly. We checked that the internal machine filter was clean and re ran it empty and the same problem occurred. We have checked the internal filter is clean (again) and followed the drainage hose and that appears to be clean too. Does this mean that the pump is broken? I saw on some other links that you can fit pumps yourself - how hard is this to do? Also, our machine has heavy usage - what should the standard life expectancy of a machine be? Thanks for your help.