I have noticed there is approx. 12mm of water left inside my dishwasher after the cycle is complete. Have check the filters and they are all clean and clear. Any suggestions as to what the problem is?
Many dishwashers use a float switch to kill the pump when the water level drops, these can get crusty with mineral/soap deposits and start acting up. Check/clean the float switch.
They also can lose pumping efficiency when the pump, pump volute, or/and discharge passages including hoses and air-gap are affected by sediment/scale/soap deposits. When the float switch tells the controller that the water level has dropped, the pump runs for a few seconds to remove the last of the water. The "few seconds" of run time does not remove as much remaining water with an occluded pump/volute/pump-out passage.
Remove, take apart, and clean the entire pump and macerator (yes, most have a macerator which is like a mini garbage grinder to break up materials that get by the screen) assemblies. And check your discharge hoses, air-gap, and drain for obstructions.